diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0ce8327..ebf7f0e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,7 @@ set(PROJECT_NAME usql)
 include_directories(${CMAKE_SOURCE_DIR}/clib ${CMAKE_SOURCE_DIR})
 
 set(SOURCE
-	exception.cpp lexer.cpp parser.cpp usql.cpp main.cpp table.cpp table.h row.cpp row.h csvreader.cpp csvreader.h ml_date.cpp settings.cpp clib/ml_string.cpp clib/linenoise.c)
+	exception.cpp lexer.cpp parser.cpp usql.cpp usql_ddl.cpp usql_dml.cpp main.cpp table.cpp row.cpp row.h csvreader.cpp ml_date.cpp settings.cpp clib/ml_string.cpp clib/linenoise.c)
 
 add_executable(${PROJECT_NAME} ${SOURCE})
 
diff --git a/lexer.cpp b/lexer.cpp
index 4015bcf..57a0c55 100644
--- a/lexer.cpp
+++ b/lexer.cpp
@@ -120,111 +120,59 @@ namespace usql {
 
     TokenType Lexer::type(const std::string &token) {
 	    // FIXME 'one is evaluated as identifier
-	    if (token == ";")
-		    return TokenType::semicolon;
-	    if (token == "+")
-		    return TokenType::plus;
-	    if (token == "-")
-		    return TokenType::minus;
-	    if (token == "*")
-		    return TokenType::multiply;
-	    if (token == "/")
-		    return TokenType::divide;
-	    if (token == "(")
-		    return TokenType::open_paren;
-	    if (token == ")")
-		    return TokenType::close_paren;
-	    if (token == "=")
-		    return TokenType::equal;
-	    if (token == "!=" || token == "<>")
-		    return TokenType::not_equal;
-	    if (token == ">")
-		    return TokenType::greater;
-	    if (token == ">=")
-		    return TokenType::greater_equal;
-	    if (token == "<")
-		    return TokenType::lesser;
-	    if (token == "<=")
-		    return TokenType::lesser_equal;
-	    if (token == "is")
-		    return TokenType::is;
-	    if (token == "as")
-		    return TokenType::keyword_as;
-	    if (token == "create")
-		    return TokenType::keyword_create;
-	    if (token == "drop")
-		    return TokenType::keyword_drop;
-	    if (token == "where")
-		    return TokenType::keyword_where;
-	    if (token == "order")
-		    return TokenType::keyword_order;
-	    if (token == "by")
-		    return TokenType::keyword_by;
-	    if (token == "offset")
-		    return TokenType::keyword_offset;
-	    if (token == "limit")
-		    return TokenType::keyword_limit;
-	    if (token == "asc")
-		    return TokenType::keyword_asc;
-	    if (token == "desc")
-		    return TokenType::keyword_desc;
-	    if (token == "from")
-		    return TokenType::keyword_from;
-	    if (token == "delete")
-		    return TokenType::keyword_delete;
-	    if (token == "table")
-		    return TokenType::keyword_table;
-	    if (token == "insert")
-		    return TokenType::keyword_insert;
-	    if (token == "into")
-		    return TokenType::keyword_into;
-	    if (token == "values")
-		    return TokenType::keyword_values;
-	    if (token == "select")
-		    return TokenType::keyword_select;
-	    if (token == "set")
-		    return TokenType::keyword_set;
-	    if (token == "copy")
-		    return TokenType::keyword_copy;
-	    if (token == "update")
-		    return TokenType::keyword_update;
-	    if (token == "load")
-		    return TokenType::keyword_load;
-	    if (token == "save")
-		    return TokenType::keyword_save;
-	    if (token == "not")
-		    return TokenType::keyword_not;
-	    if (token == "null")
-		    return TokenType::keyword_null;
-	    if (token == "integer")
-		    return TokenType::keyword_integer;
-	    if (token == "float")
-		    return TokenType::keyword_float;
-	    if (token == "varchar")
-		    return TokenType::keyword_varchar;
-	    if (token == "date")
-		    return TokenType::keyword_date;
-	    if (token == "boolean")
-		    return TokenType::keyword_bool;
-	    if (token == "true")
-		    return TokenType::keyword_true;
-	    if (token == "false")
-		    return TokenType::keyword_false;
-	    if (token == "distinct")
-		    return TokenType::keyword_distinct;
-	    if (token == "show")
-		    return TokenType::keyword_show;
-	    if (token == "or")
-		    return TokenType::logical_or;
-	    if (token == "and")
-		    return TokenType::logical_and;
-	    if (token == ",")
-		    return TokenType::comma;
-	    if (token == "\n" || token == "\r\n" || token == "\r")
-		    return TokenType::newline;
+	    if (token == ";") return TokenType::semicolon;
+	    if (token == "+") return TokenType::plus;
+	    if (token == "-") return TokenType::minus;
+	    if (token == "*") return TokenType::multiply;
+	    if (token == "/") return TokenType::divide;
+	    if (token == "(") return TokenType::open_paren;
+	    if (token == ")") return TokenType::close_paren;
+	    if (token == "=") return TokenType::equal;
+	    if (token == "!=" || token == "<>") return TokenType::not_equal;
+	    if (token == ">") return TokenType::greater;
+	    if (token == ">=") return TokenType::greater_equal;
+	    if (token == "<") return TokenType::lesser;
+	    if (token == "<=") return TokenType::lesser_equal;
+	    if (token == "is") return TokenType::is;
+	    if (token == "as") return TokenType::keyword_as;
+	    if (token == "create") return TokenType::keyword_create;
+	    if (token == "drop") return TokenType::keyword_drop;
+	    if (token == "where") return TokenType::keyword_where;
+	    if (token == "order") return TokenType::keyword_order;
+	    if (token == "by") return TokenType::keyword_by;
+	    if (token == "offset") return TokenType::keyword_offset;
+	    if (token == "limit") return TokenType::keyword_limit;
+	    if (token == "asc") return TokenType::keyword_asc;
+	    if (token == "desc") return TokenType::keyword_desc;
+	    if (token == "from") return TokenType::keyword_from;
+	    if (token == "delete") return TokenType::keyword_delete;
+	    if (token == "table") return TokenType::keyword_table;
+	    if (token == "insert") return TokenType::keyword_insert;
+	    if (token == "into") return TokenType::keyword_into;
+	    if (token == "values") return TokenType::keyword_values;
+	    if (token == "select") return TokenType::keyword_select;
+	    if (token == "set") return TokenType::keyword_set;
+	    if (token == "copy") return TokenType::keyword_copy;
+	    if (token == "update") return TokenType::keyword_update;
+	    if (token == "load") return TokenType::keyword_load;
+	    if (token == "save") return TokenType::keyword_save;
+	    if (token == "not") return TokenType::keyword_not;
+	    if (token == "null") return TokenType::keyword_null;
+	    if (token == "integer") return TokenType::keyword_integer;
+	    if (token == "float") return TokenType::keyword_float;
+	    if (token == "varchar") return TokenType::keyword_varchar;
+	    if (token == "date") return TokenType::keyword_date;
+	    if (token == "boolean") return TokenType::keyword_bool;
+	    if (token == "true") return TokenType::keyword_true;
+	    if (token == "false") return TokenType::keyword_false;
+	    if (token == "distinct") return TokenType::keyword_distinct;
+	    if (token == "show") return TokenType::keyword_show;
+	    if (token == "or") return TokenType::logical_or;
+	    if (token == "and") return TokenType::logical_and;
+	    if (token == ",") return TokenType::comma;
+	    if (token == "\n" || token == "\r\n" || token == "\r") return TokenType::newline;
 
-	    if (token.length() > 1 && token.at(0) == '%' &&
-		(token.at(token.length() - 1) == '\n' || token.at(token.length() - 1) == '\r'))
+	    if (token.length() > 1 && token.at(0) == '%' && (token.at(token.length() - 1) == '\n' || token.at(token.length() - 1) == '\r'))
 		    return TokenType::comment;
 
 	    if (token.length() >= 2 && token.at(0) == '"' && token.at(token.length() - 1) == '"')
@@ -233,17 +181,10 @@ namespace usql {
 	    if (token.length() >= 2 && token.at(0) == '\'' && token.at(token.length() - 1) == '\'')
 		    return TokenType::string_literal;
 
-	    if (std::regex_match(token, k_int_regex))
-		    return TokenType::int_number;
-
-	    if (std::regex_match(token, k_int_underscored_regex))
-		    return TokenType::int_number;
-
-	    if (std::regex_match(token, k_double_regex))
-		    return TokenType::double_number;
-
-	    if (std::regex_match(token, k_identifier_regex))
-		    return TokenType::identifier;
+	    if (std::regex_match(token, k_int_regex)) return TokenType::int_number;
+	    if (std::regex_match(token, k_int_underscored_regex)) return TokenType::int_number;
+	    if (std::regex_match(token, k_double_regex)) return TokenType::double_number;
+	    if (std::regex_match(token, k_identifier_regex)) return TokenType::identifier;
 
 	    return TokenType::undef;
     }
@@ -286,178 +227,65 @@ namespace usql {
     }
 
     std::string Lexer::typeToString(TokenType token_type) {
-	    std::string txt;
 	    switch (token_type) {
-		    case TokenType::undef:
-			    txt = "undef";
-			    break;
-		    case TokenType::identifier:
-			    txt = "identifier";
-			    break;
-		    case TokenType::plus:
-			    txt = "+";
-			    break;
-		    case TokenType::minus:
-			    txt = "-";
-			    break;
-		    case TokenType::multiply:
-			    txt = "*";
-			    break;
-		    case TokenType::divide:
-			    txt = "/";
-			    break;
-		    case TokenType::equal:
-			    txt = "==";
-			    break;
-		    case TokenType::not_equal:
-			    txt = "!=";
-			    break;
-		    case TokenType::greater:
-			    txt = ">";
-			    break;
-		    case TokenType::greater_equal:
-			    txt = ">=";
-			    break;
-		    case TokenType::lesser:
-			    txt = "<";
-			    break;
-		    case TokenType::lesser_equal:
-			    txt = "<=";
-			    break;
-		    case TokenType::is:
-			    txt = "is";
-			    break;
-		    case TokenType::keyword_as:
-			    txt = "as";
-			    break;
-		    case TokenType::keyword_create:
-			    txt = "create";
-			    break;
-		    case TokenType::keyword_drop:
-			    txt = "drop";
-			    break;
-		    case TokenType::keyword_where:
-			    txt = "where";
-			    break;
-		    case TokenType::keyword_order:
-			    txt = "order";
-			    break;
-		    case TokenType::keyword_by:
-			    txt = "by";
-			    break;
-		    case TokenType::keyword_offset:
-			    txt = "offset";
-			    break;
-		    case TokenType::keyword_limit:
-			    txt = "limit";
-			    break;
-		    case TokenType::keyword_asc:
-			    txt = "asc";
-			    break;
-		    case TokenType::keyword_desc:
-			    txt = "desc";
-			    break;
-		    case TokenType::keyword_table:
-			    txt = "table";
-			    break;
-		    case TokenType::keyword_into:
-			    txt = "into";
-			    break;
-		    case TokenType::keyword_values:
-			    txt = "values";
-			    break;
-		    case TokenType::keyword_select:
-			    txt = "select";
-			    break;
-		    case TokenType::keyword_set:
-			    txt = "set";
-			    break;
-		    case TokenType::keyword_copy:
-			    txt = "copy";
-			    break;
-		    case TokenType::keyword_update:
-			    txt = "update";
-			    break;
-		    case TokenType::keyword_load:
-			    txt = "load";
-			    break;
-		    case TokenType::keyword_save:
-			    txt = "save";
-			    break;
-		    case TokenType::keyword_not:
-			    txt = "not";
-			    break;
-		    case TokenType::keyword_null:
-			    txt = "null";
-			    break;
-		    case TokenType::keyword_integer:
-			    txt = "integer";
-			    break;
-		    case TokenType::keyword_float:
-			    txt = "float";
-			    break;
-		    case TokenType::keyword_varchar:
-			    txt = "varchar";
-			    break;
-		    case TokenType::keyword_date:
-			    txt = "date";
-			    break;
-		    case TokenType::keyword_bool:
-			    txt = "boolean";
-			    break;
-		    case TokenType::keyword_true:
-			    txt = "true";
-			    break;
-		    case TokenType::keyword_false:
-			    txt = "false";
-			    break;
-		    case TokenType::keyword_distinct:
-			    txt = "distinct";
-			    break;
-		    case TokenType::keyword_show:
-			    txt = "show";
-			    break;
-		    case TokenType::int_number:
-			    txt = "int number";
-			    break;
-		    case TokenType::double_number:
-			    txt = "double number";
-			    break;
-		    case TokenType::string_literal:
-			    txt = "string literal";
-			    break;
-		    case TokenType::open_paren:
-			    txt = "(";
-			    break;
-		    case TokenType::close_paren:
-			    txt = ")";
-			    break;
-		    case TokenType::logical_and:
-			    txt = "and";
-			    break;
-		    case TokenType::logical_or:
-			    txt = "or";
-			    break;
-		    case TokenType::semicolon:
-			    txt = ";";
-			    break;
-		    case TokenType::comma:
-			    txt = ",";
-			    break;
-		    case TokenType::newline:
-			    txt = "newline";
-			    break;
-		    case TokenType::comment:
-			    txt = "comment";
-			    break;
-		    case TokenType::eof:
-			    txt = "eof";
-			    break;
+		    case TokenType::undef: return "undef";
+		    case TokenType::identifier: return "identifier";
+		    case TokenType::plus: return "+";
+		    case TokenType::minus: return "-";
+		    case TokenType::multiply: return "*";
+		    case TokenType::divide: return "/";
+		    case TokenType::equal: return "==";
+		    case TokenType::not_equal: return "!=";
+		    case TokenType::greater: return ">";
+		    case TokenType::greater_equal: return ">=";
+		    case TokenType::lesser: return "<";
+		    case TokenType::lesser_equal: return "<=";
+		    case TokenType::is: return "is";
+		    case TokenType::keyword_as: return "as";
+		    case TokenType::keyword_create: return "create";
+		    case TokenType::keyword_drop: return "drop";
+		    case TokenType::keyword_where: return "where";
+		    case TokenType::keyword_order: return "order";
+		    case TokenType::keyword_by: return "by";
+		    case TokenType::keyword_offset: return "offset";
+		    case TokenType::keyword_limit: return "limit";
+		    case TokenType::keyword_asc: return "asc";
+		    case TokenType::keyword_desc: return "desc";
+		    case TokenType::keyword_table: return "table";
+		    case TokenType::keyword_into: return "into";
+		    case TokenType::keyword_values: return "values";
+		    case TokenType::keyword_select: return "select";
+		    case TokenType::keyword_set: return "set";
+		    case TokenType::keyword_copy: return "copy";
+		    case TokenType::keyword_update: return "update";
+		    case TokenType::keyword_load: return "load";
+		    case TokenType::keyword_save: return "save";
+		    case TokenType::keyword_not: return "not";
+		    case TokenType::keyword_null: return "null";
+		    case TokenType::keyword_integer: return "integer";
+		    case TokenType::keyword_float: return "float";
+		    case TokenType::keyword_varchar: return "varchar";
+		    case TokenType::keyword_date: return "date";
+		    case TokenType::keyword_bool: return "boolean";
+		    case TokenType::keyword_true: return "true";
+		    case TokenType::keyword_false: return "false";
+		    case TokenType::keyword_distinct: return "distinct";
+		    case TokenType::keyword_show: return "show";
+		    case TokenType::int_number: return "int number";
+		    case TokenType::double_number: return "double number";
+		    case TokenType::string_literal: return "string literal";
+		    case TokenType::open_paren: return "(";
+		    case TokenType::close_paren: return ")";
+		    case TokenType::logical_and: return "and";
+		    case TokenType::logical_or: return "or";
+		    case TokenType::semicolon: return ";";
+		    case TokenType::comma: return ",";
+		    case TokenType::newline: return "newline";
+		    case TokenType::comment: return "comment";
+		    case TokenType::eof: return "eof";
 		    default:
-			    txt = "FIXME, unknown token type";
-			    break;
+			    return "FIXME, unknown token type";
 	    }
-	    return txt;
     }
 
 }
\ No newline at end of file
diff --git a/main.cpp b/main.cpp
index efc63d7..49c4257 100644
--- a/main.cpp
+++ b/main.cpp
@@ -148,24 +148,27 @@ void debug() {
 		    "insert into a (i, s, b) values(1, upper('zero'), 'Y')",
 		    "insert into a (i, s, b, f) values(1 + 10000, upper('one'), 'N', 3.1415)",
 		    "insert into a (i, s, f) values(2 + 10000, upper('two'), 3.1415)",
+		    "select min(i), max(i), count(*) from a where b is not null",
 		    "select * from a where b is null",
 		    "select * from a where b is not null",
-//		    "select * from a where b='N'",
-//		    "update a set i = i * 100, f = f + 0.01 where i > 1",
-//		    "select to_string(i, '%d.%m.%Y %H:%M:%S'), i, s from a where i < to_date('20.12.2019', '%d.%m.%Y')",
-//		    "select i + 2 as first, i, s, b, f from a where i >=1 order by 1 desc offset 0 limit 1",
-//		    "update table a set s = 'null string aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'",
-//		    "update table a set i = null",
-//		    "insert into a (i, s) values(2, 'two')",
-//		    "insert into a (i, s) values(3, 'two')",
-//		    "insert into a (i, s) values(4, lower('FOUR'))",
-//		    "insert into a (i, s) values(5, 'five')",
-//		    "insert into a (i, s) values(to_date('20.12.1973', '%d.%m.%Y'), 'six')",
+		    "select * from a where b='N'",
+		    "update a set i = i * 100, f = f + 0.01 where i > 1",
+		    "select to_string(i, '%d.%m.%Y %H:%M:%S'), i, s from a where i < to_date('20.12.2019', '%d.%m.%Y')",
+		    "select i + 2 as first, i, s, b, f from a where i >=1 order by 1 desc offset 0 limit 1",
+
+
+		    "update table a set s = 'null string aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'",
+		    "update table a set i = null",
+		    "insert into a (i, s) values(2, 'two')",
+		    "insert into a (i, s) values(3, 'two')",
+		    "insert into a (i, s) values(4, lower('FOUR'))",
+		    "insert into a (i, s) values(5, 'five')",
+		    "insert into a (i, s) values(to_date('20.12.1973', '%d.%m.%Y'), 'six')",
 		    // tohle zpusobi kresh		    "insert into a (i, d) values(6', '2006-10-04')",
-//		    "insert into a (i, d) values(6, '2006-10-04')",
-//		    "save table a into '/tmp/a.csv'",
-//		    "select i, s from a where i > 2 order by 1 desc offset 1 limit 1",
-//		    "select distinct s, d from a",
+		    "insert into a (i, d) values(6, '2006-10-04')",
+		    "save table a into '/tmp/a.csv'",
+		    "select i, s from a where i > 2 order by 1 desc offset 1 limit 1",
+		    "select distinct s, d from a",
 //		    "select i, s from a where i = 1",
 //		    "select i, s from a where s = 'two'",
 //		    "select i, s from a where i <= 3 and s = 'one'",
diff --git a/parser.cpp b/parser.cpp
index 8bc7fdc..e7f5c36 100644
--- a/parser.cpp
+++ b/parser.cpp
@@ -191,8 +191,10 @@ namespace usql {
 	    // column values
 	    m_lexer.skipToken(TokenType::open_paren);
 	    do {
-		    auto col_value =  parse_expression();
-		    column_values.push_back(std::move(col_value));
+		    // TODO here it is problem when exception from parse_expression<-parse_value is thrown
+		    // it makes double free
+		    auto value = parse_expression();
+		    column_values.emplace_back(std::move(value));
 
 		    m_lexer.skipTokenOptional(TokenType::comma);
 	    } while (m_lexer.tokenType() != TokenType::close_paren);
@@ -408,7 +410,6 @@ namespace usql {
 	    // parenthesised expression
 	    if (token_type == TokenType::open_paren) {
             m_lexer.skipToken(TokenType::open_paren);
-            
 		    auto left = parse_expression();
 		    do {
 			left = parse_expression(std::move(left));
@@ -454,6 +455,10 @@ namespace usql {
 	    if (token_type == TokenType::keyword_true || token_type == TokenType::keyword_false)
 		return std::make_unique<BooleanValueNode>(token_type == TokenType::keyword_true);
 
+	    // token * for count(*)
+	    if (token_type == TokenType::multiply)
+		    return std::make_unique<StringValueNode>(tokenString);
+
 	    throw Exception("Unknown operand node " + tokenString);
     }
 
diff --git a/usql.cpp b/usql.cpp
index ca05bf1..518c622 100644
--- a/usql.cpp
+++ b/usql.cpp
@@ -50,357 +50,15 @@ std::unique_ptr<Table> USql::execute(Node &node) {
 }
 
 
-std::unique_ptr<Table> USql::execute_create_table(CreateTableNode &node) {
-	check_table_not_exists(node.table_name);
-
-	Table table{node.table_name, node.cols_defs};
-	m_tables.push_back(table);
-
-	return create_stmt_result_table(0, "table created", 0);
-}
-
-
-std::unique_ptr<Table> USql::execute_create_table_as_table(CreateTableAsSelectNode &node) {
-	check_table_not_exists(node.table_name);
-
-	auto select = execute_select((SelectFromTableNode &) *node.select_table);
-
-	// create table
-	Table new_table{node.table_name, select->m_col_defs};
-	m_tables.push_back(new_table);
-
-	// copy rows
-	// must be here, if rows are put into new_table, they are lost during m_tables.push_table
-	Table *table = find_table(node.table_name);
-	for( Row& orig_row : select->m_rows) {
-		table->commit_copy_of_row(orig_row);
-	}
-
-	select.release();	// is it correct? hoping not to release select table here and then when releasing CreateTableAsSelectNode
-
-	return create_stmt_result_table(0, "table created", table->m_rows.size());
-}
-
-
-
-std::unique_ptr<Table> USql::execute_load(LoadIntoTableNode &node) {
-	// find source table
-	Table *table_def = find_table(node.table_name);
-
-	// read data
-	// std::ifstream ifs(node.filename);
-	// std::string content((std::istreambuf_iterator<char>(ifs)),
-	// 		    (std::istreambuf_iterator<char>()));
-	// load rows
-	// auto rows_cnt = table_def->load_csv_string(content);
-
-
-	auto rows_cnt = table_def->load_csv_file(node.filename);
-
-	return create_stmt_result_table(0, "load succeeded", rows_cnt);
-}
-
-
-std::unique_ptr<Table> USql::execute_save(SaveTableNode &node) {
-	// find source table
-	Table *table_def = find_table(node.table_name);
-
-	// make csv string
-	std::string csv_string = table_def->csv_string();
-
-	// save data
-	std::ofstream file(node.filename);
-	file << csv_string;
-	file.close();
-
-	return create_stmt_result_table(0, "save succeeded", table_def->rows_count());
-}
-
-std::unique_ptr<Table> USql::execute_drop(DropTableNode &node) {
-	auto name_cmp = [node](const Table& t) { return t.m_name == node.table_name; };
-
-	auto table_def = std::find_if(begin(m_tables), end(m_tables), name_cmp);
-	if (table_def != std::end(m_tables)) {
-		m_tables.erase(table_def);
-		return create_stmt_result_table(0, "drop succeeded", 0);
-	}
-
-	throw Exception("table not found (" + node.table_name + ")");
-}
-
-std::unique_ptr<Table> USql::execute_set(SetNode &node) {
-	Settings::set_setting(node.name, node.value);
-	return create_stmt_result_table(0, "set succeeded", 1);
-}
-
-std::unique_ptr<Table> USql::execute_show(ShowNode &node) {
-	std::string value = Settings::get_setting(node.name);
-	return create_stmt_result_table(0, "show succeeded: " + value, 1);
-}
-
-std::unique_ptr<Table> USql::execute_insert_into_table(InsertIntoTableNode &node) {
-	// find table
-	Table *table_def = find_table(node.table_name);
-
-	if (node.cols_names.size() != node.cols_values.size())
-		throw Exception("Incorrect number of values");
-
-	// prepare empty new_row
-	Row& new_row = table_def->create_empty_row();
-
-	// copy values
-	for (size_t i = 0; i < node.cols_names.size(); i++) {
-		ColDefNode col_def = table_def->get_column_def(node.cols_names[i].col_name);
-		auto col_value = eval_value_node(table_def, new_row, node.cols_values[i].get());
-
-		new_row.setColumnValue(&col_def, col_value.get());
-	}
-
-	// append new_row
-	table_def->commit_row(new_row);
-
-	return create_stmt_result_table(0, "insert succeeded", 1);
-}
-
-
-std::unique_ptr<Table> USql::execute_select(SelectFromTableNode &node) {
-	// find source table
-	Table *table = find_table(node.table_name);
-
-	// expand *
-	if (node.cols_names->size()==1 && node.cols_names->operator[](0).name == "*") {
-		node.cols_names->clear();
-		node.cols_names->reserve(table->columns_count());
-		for(const auto& col : table->m_col_defs) {
-			node.cols_names->emplace_back(SelectColNode{std::make_unique<DatabaseValueNode>(col.name), col.name});
-		}
-	}
-
-
-	// create result table
-	std::vector<ColDefNode> result_tbl_col_defs{};
-	std::vector<int> source_table_col_index{};
-
-	for (int i = 0; i < node.cols_names->size(); i++) {
-		auto [src_tbl_col_index, rst_tbl_col_def] = get_column_definition(table, &node.cols_names->operator[](i), i);
-
-		source_table_col_index.push_back(src_tbl_col_index);
-		result_tbl_col_defs.push_back(rst_tbl_col_def);
-	}
-	auto result = std::make_unique<Table>("result", result_tbl_col_defs);
-
-
-	// execute access plan
-	for (auto row = begin(table->m_rows); row != end(table->m_rows); ++row) {
-		// eval where for row
-		if (eval_where(node.where.get(), table, *row)) {
-			// prepare empty row and copy column values
-			Row& new_row = result->create_empty_row();
-
-			for (auto idx = 0; idx < result->columns_count(); idx++) {
-				auto row_col_index = source_table_col_index[idx];
-
-				if (row_col_index == FUNCTION_CALL) {
-					auto evaluated_value = eval_value_node(table, *row, node.cols_names->operator[](idx).value.get());
-					ValueNode *col_value = evaluated_value.get();
-
-					new_row.setColumnValue(&result_tbl_col_defs[idx], col_value);
-				} else {
-					ColValue &col_value = row->operator[](row_col_index);
-					new_row.setColumnValue(&result_tbl_col_defs[idx], col_value);
-				}
-			}
-
-			// add row to result
-			result->commit_row(new_row);
-		}
-	}
-
-	execute_distinct(node, result.get());
-
-	execute_order_by(node, table, result.get());
-
-	execute_offset_limit(node.offset_limit, result.get());
-
-	return result;
-}
-
-void USql::execute_distinct(SelectFromTableNode &node, Table *result) {
-	if (!node.distinct) return;
-	
-	auto compare_rows = [](const Row &a, const Row &b) { return a.compare(b) >= 0; };
-	std::sort(result->m_rows.begin(), result->m_rows.end(), compare_rows);
-
-	result->m_rows.erase(std::unique(result->m_rows.begin(), result->m_rows.end()), result->m_rows.end());
-}
-
-void USql::execute_order_by(SelectFromTableNode &node, Table *table, Table *result) {
-	if (node.order_by.empty()) return;
-
-	auto compare_rows = [&node, &result](const Row &a, const Row &b) {
-		for(const auto& order_by_col_def : node.order_by) {
-			// TODO validate index
-			ColDefNode col_def = result->get_column_def(order_by_col_def.col_index - 1);
-			ColValue &a_val = a[col_def.order];
-			ColValue &b_val = b[col_def.order];
-
-			int compare = a_val.compare(b_val);
-
-			if (compare < 0) return order_by_col_def.ascending;
-			if (compare > 0) return !order_by_col_def.ascending;
-		}
-	     return false;
-	};
-
-	std::sort(result->m_rows.begin(), result->m_rows.end(), compare_rows);
-}
-
-void USql::execute_offset_limit(OffsetLimitNode &node, Table *result) {
-	if (node.offset > 0)
-		result->m_rows.erase(result->m_rows.begin(),
-				     result->rows_count() > node.offset ? result->m_rows.begin() + node.offset : result->m_rows.end());
-
-	if (node.limit > 0 && node.limit < result->rows_count())
-		result->m_rows.erase(result->m_rows.begin() + node.limit, result->m_rows.end());
-}
-
-std::tuple<int, ColDefNode> USql::get_column_definition(Table *table, SelectColNode *select_col_node, int col_order ) {
-	return get_node_definition(table, select_col_node->value.get(), select_col_node->name, col_order );
-}
-
-std::tuple<int, ColDefNode> USql::get_node_definition(Table *table, Node * node, const std::string & col_name, int col_order ) {
-	if (node->node_type == NodeType::database_value) {
-		auto dbval_node = static_cast<DatabaseValueNode *>(node);
-
-		ColDefNode src_col_def = table->get_column_def(dbval_node->col_name);
-		ColDefNode col_def = ColDefNode{col_name, src_col_def.type, col_order, src_col_def.length, src_col_def.null};
-		return std::make_tuple(src_col_def.order, col_def);
-
-	} else if (node->node_type == NodeType::function) {
-		auto func_node = static_cast<FunctionNode *>(node);
-
-		if (func_node->function == "to_string") {
-			ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 32, true};
-			return std::make_tuple(-1, col_def);
-		} else if (func_node->function == "to_date") {
-			ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
-			return std::make_tuple(-1, col_def);
-		} else if (func_node->function == "pp") {
-			ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 10, true};
-			return std::make_tuple(-1, col_def);
-		}
-		throw Exception("Unsupported function");
-
-	} else if (node->node_type == NodeType::arithmetical_operator) {
-		auto ari_node = static_cast<ArithmeticalOperatorNode *>(node);
-
-		auto [left_col_index, left_tbl_col_def] = get_node_definition(table, ari_node->left.get(), col_name, col_order );
-		auto [right_col_index, right_tbl_col_def] = get_node_definition(table, ari_node->right.get(), col_name, col_order );
-
-		ColumnType col_type;	// TODO handle varchar and it len
-		if (left_tbl_col_def.type==ColumnType::float_type || right_tbl_col_def.type==ColumnType::float_type)
-			col_type = ColumnType::float_type;
-		else
-			col_type = ColumnType::integer_type;
-
-		ColDefNode col_def = ColDefNode{col_name, col_type, col_order, 1, true};
-		return std::make_tuple(-1, col_def);
-
-	} else if (node->node_type == NodeType::logical_operator) {
-		ColDefNode col_def = ColDefNode{col_name, ColumnType::bool_type, col_order, 1, true};
-		return std::make_tuple(-1, col_def);
-
-	} else if (node->node_type == NodeType::int_value) {
-		ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
-		return std::make_tuple(-1, col_def);
-
-	} else if (node->node_type == NodeType::float_value) {
-		ColDefNode col_def = ColDefNode{col_name, ColumnType::float_type, col_order, 1, true};
-		return std::make_tuple(-1, col_def);
-
-	} else if (node->node_type == NodeType::string_value) {
-		// TODO right len
-		ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 64, true};
-		return std::make_tuple(-1, col_def);
-	}
-	throw Exception("Unsupported node type");
-}
-
-
-
-std::unique_ptr<Table> USql::execute_delete(DeleteFromTableNode &node) {
-	// find source table
-	Table *table = find_table(node.table_name);
-
-	// execute access plan
-	auto affected_rows = table->rows_count();
-
-	table->m_rows.erase(
-		std::remove_if(table->m_rows.begin(), table->m_rows.end(), 
-				[&node, table](Row &row){return eval_where(node.where.get(), table, row);}),
-		table->m_rows.end());
-
-	affected_rows -= table->rows_count();
-
-	return create_stmt_result_table(0, "delete succeeded", affected_rows);
-}
-
-
-std::unique_ptr<Table> USql::execute_update(UpdateTableNode &node) {
-	// find source table
-	Table *table = find_table(node.table_name);
-
-	// execute access plan
-	int affected_rows = 0;
-	for (auto row = begin(table->m_rows); row != end(table->m_rows); ++row) {
-		// eval where for row
-		if (eval_where(node.where.get(), table, *row)) {
-			int i = 0;
-			for (const auto& col : node.cols_names) {
-				// TODO cache it like in select
-				ColDefNode col_def = table->get_column_def(col.col_name);
-				std::unique_ptr<ValueNode> new_val = eval_arithmetic_operator(col_def.type,
-											      static_cast<ArithmeticalOperatorNode &>(*node.values[i]),
-											      table, *row);
-
-				usql::Table::validate_column(&col_def, new_val.get());
-				row->setColumnValue(&col_def, new_val.get());
-				i++;
-			}
-			affected_rows++;
-			// TODO tady je problem, ze kdyz to zfajluje na jednom radku ostatni by se nemely provest
-		}
-	}
-
-	return create_stmt_result_table(0, "update succeeded", affected_rows);
-}
-
-
-bool USql::eval_where(Node *where, Table *table, Row &row) {
-	switch (where->node_type) {
-		case NodeType::true_node:
-			return true;
-		case NodeType::relational_operator:     //  just one condition
-			return eval_relational_operator(*((RelationalOperatorNode *) where), table, row);
-		case NodeType::logical_operator:
-			return eval_logical_operator(*((LogicalOperatorNode *) where), table, row);
-		default:
-			throw Exception("Wrong node type");
-	}
-
-	return false;
-}
-
-
 bool USql::eval_relational_operator(const RelationalOperatorNode &filter, Table *table, Row &row) {
-	std::unique_ptr<ValueNode> left_value = eval_value_node(table, row, filter.left.get());
-	std::unique_ptr<ValueNode> right_value = eval_value_node(table, row, filter.right.get());
+	std::unique_ptr<ValueNode> left_value = eval_value_node(table, row, filter.left.get(), nullptr, nullptr);
+	std::unique_ptr<ValueNode> right_value = eval_value_node(table, row, filter.right.get(), nullptr, nullptr);
 
 	double comparator;
 
 	if (left_value->node_type == NodeType::null_value || right_value->node_type == NodeType::null_value) {
-		bool all_null = left_value->isNull()  && right_value->node_type == NodeType::null_value ||
-				right_value->isNull() && left_value->node_type == NodeType::null_value;
+		bool all_null = (left_value->isNull() && right_value->node_type == NodeType::null_value) ||
+				(right_value->isNull() && left_value->node_type == NodeType::null_value);
 		if (filter.op == RelationalOperatorType::is)
 			return all_null;
 		if (filter.op == RelationalOperatorType::is_not)
@@ -436,19 +94,23 @@ bool USql::eval_relational_operator(const RelationalOperatorNode &filter, Table
 			return comparator < 0.0;
 		case RelationalOperatorType::lesser_equal:
 			return comparator <= 0.0;
+		case RelationalOperatorType::is:
+		case RelationalOperatorType::is_not:
+			// already handled
+			throw Exception("error in is or is not handling");
 	}
 
 	throw Exception("invalid relational operator");
 }
 
 
-std::unique_ptr<ValueNode> USql::eval_value_node(Table *table, Row &row, Node *node) {
+std::unique_ptr<ValueNode> USql::eval_value_node(Table *table, Row &row, Node *node, ColDefNode *col_def_node, ColValue *agg_func_value) {
 	if (node->node_type == NodeType::database_value) {
 		return eval_database_value_node(table, row, node);
 	} else if (node->node_type == NodeType::int_value || node->node_type == NodeType::float_value || node->node_type == NodeType::string_value || node->node_type == NodeType::bool_value) {
 		return eval_literal_value_node(table, row, node);
 	} else if (node->node_type == NodeType::function) {
-		return eval_function_value_node(table, row, node);
+		return eval_function_value_node(table, row, node, col_def_node, agg_func_value);
 	} else if (node->node_type == NodeType::null_value) {
 		return std::make_unique<NullValueNode>();
 	} else if (node->node_type == NodeType::arithmetical_operator) {
@@ -504,12 +166,13 @@ std::unique_ptr<ValueNode> USql::eval_literal_value_node(Table *table, Row &row,
 }
 
 
-std::unique_ptr<ValueNode> USql::eval_function_value_node(Table *table, Row &row, Node *node) {
+std::unique_ptr<ValueNode>
+USql::eval_function_value_node(Table *table, Row &row, Node *node, ColDefNode *col_def_node, ColValue *agg_func_value) {
 	auto  *fnc = static_cast<FunctionNode *>(node);
 
 	std::vector<std::unique_ptr<ValueNode>> evaluatedPars;
 	for(auto & param : fnc->params) {
-		evaluatedPars.push_back(eval_value_node(table, row, param.get()));
+		evaluatedPars.push_back(eval_value_node(table, row, param.get(), nullptr, nullptr));
 	}
 
 	// at this moment no functions without parameter(s) or first param can be null
@@ -517,69 +180,24 @@ std::unique_ptr<ValueNode> USql::eval_function_value_node(Table *table, Row &row
 		return std::make_unique<NullValueNode>();
 
 	// TODO use some enum
-	if (fnc->function == "lower") {
-		std::string str = evaluatedPars[0]->getStringValue();
-		std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) -> unsigned char { return std::tolower(c); });
-		return std::make_unique<StringValueNode>(str);
+	if (fnc->function == "lower") return lower_function(evaluatedPars);
+	if (fnc->function == "upper") return upper_function(evaluatedPars);
+	if (fnc->function == "to_date") return to_date_function(evaluatedPars);
+	if (fnc->function == "to_string") return to_string_function(evaluatedPars);
+	if (fnc->function == "pp") return pp_function(evaluatedPars);
+	if (fnc->function == "count") return count_function(agg_func_value, evaluatedPars);
+	if (fnc->function == "max") return max_function(evaluatedPars, col_def_node, agg_func_value);
+	if (fnc->function == "min") return min_function(evaluatedPars, col_def_node, agg_func_value);
+
+	throw Exception("invalid function: " + fnc->function);
+}
+
+std::unique_ptr<ValueNode> USql::count_function(ColValue *agg_func_value, const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	long c = 1;
+	if (!agg_func_value->isNull()) {
+		c = agg_func_value->getIntValue() + 1;
 	}
-	if (fnc->function == "upper") {
-		std::string str = evaluatedPars[0]->getStringValue();
-		std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) -> unsigned char { return std::toupper(c); });
-		return std::make_unique<StringValueNode>(str);
-	}
-
-	if (fnc->function == "to_date") {
-		std::string date = evaluatedPars[0]->getStringValue();
-		std::string format = evaluatedPars[1]->getStringValue();
-		long epoch_time = string_to_date(date, format);
-		return std::make_unique<IntValueNode>(epoch_time);	// No DateValueNode for now
-	}
-	if (fnc->function == "to_string") {
-		long date = evaluatedPars[0]->getDateValue();
-		std::string format = evaluatedPars[1]->getStringValue();
-		std::string formatted_date = date_to_string(date, format);
-		return std::make_unique<StringValueNode>(formatted_date);
-	}
-	if (fnc->function == "pp") {
-		auto &parsed_value = evaluatedPars[0];
-
-		if (parsed_value->node_type == NodeType::int_value || parsed_value->node_type == NodeType::float_value) {
-			std::string format = evaluatedPars.size() > 1 ? evaluatedPars[1]->getStringValue() : "";
-			char buf[16] {0};
-			double value = parsed_value->getDoubleValue(); 
-
-			if (format == "100%")
-				std::snprintf(buf, 20, "%.2f%%", value);
-			else if (value >= 1000000000000)
-				std::snprintf(buf, 20, "%7.2fT", value/1000000000000);
-			else if (value >= 1000000000)
-				std::sprintf(buf, "%7.2fB", value/1000000000);
-			else if (value >= 1000000)
-				std::snprintf(buf, 20, "%7.2fM", value/1000000);
-			else if (value >= 100000)
-				std::snprintf(buf, 20, "%7.2fM", value/100000);	// 0.12M
-			else if (value <= -1000000000000)
-				std::snprintf(buf, 20, "%7.2fT", value/1000000000000);
-			else if (value <= -1000000000)
-				std::snprintf(buf, 20, "%7.2fB", value/1000000000);
-			else if (value <= -1000000)
-				std::snprintf(buf, 20, "%7.2fM", value/1000000);
-			else if (value <= -100000)
-				std::snprintf(buf, 20, "%7.2fM", value/100000);	// 0.12M
-			else if (value == 0)
-				buf[0]='0';
-			else
-				return std::make_unique<StringValueNode>(parsed_value->getStringValue().substr(0, 10));
-			// TODO introduce constant for 10
-			std::string s {buf};
-			return std::make_unique<StringValueNode>(string_padd(s.erase(s.find_last_not_of(" ")+1), 10, ' ', false));
-		}
-
-		return std::make_unique<StringValueNode>(parsed_value->getStringValue());
-	}
-
-
-	throw Exception("invalid function");
+	return std::make_unique<IntValueNode>(c);
 }
 
 
@@ -598,11 +216,11 @@ bool USql::eval_logical_operator(LogicalOperatorNode &node, Table *pTable, Row &
 
 std::unique_ptr<ValueNode> USql::eval_arithmetic_operator(ColumnType outType, ArithmeticalOperatorNode &node, Table *table, Row &row) {
 	if (node.op == ArithmeticalOperatorType::copy_value) {
-		return eval_value_node(table, row, node.left.get());
+		return eval_value_node(table, row, node.left.get(), nullptr, nullptr);
 	}
 
-	std::unique_ptr<ValueNode> left = eval_value_node(table, row, node.left.get());
-	std::unique_ptr<ValueNode> right = eval_value_node(table, row, node.right.get());
+	std::unique_ptr<ValueNode> left = eval_value_node(table, row, node.left.get(), nullptr, nullptr);
+	std::unique_ptr<ValueNode> right = eval_value_node(table, row, node.right.get(), nullptr, nullptr);
 
 	if (left->isNull() || right->isNull())
 		return std::make_unique<NullValueNode>();
@@ -655,24 +273,130 @@ std::unique_ptr<ValueNode> USql::eval_arithmetic_operator(ColumnType outType, Ar
 }
 
 
-std::unique_ptr<Table> USql::create_stmt_result_table(long code, const std::string &text, size_t affected_rows) {
-	std::vector<ColDefNode> result_tbl_col_defs{};
-	result_tbl_col_defs.emplace_back("code", ColumnType::integer_type, 0, 1, false);
-	result_tbl_col_defs.emplace_back("desc", ColumnType::varchar_type, 1, 48, false);
-	result_tbl_col_defs.emplace_back("affected_rows", ColumnType::integer_type, 0, 1, true);
-
-	auto table_def = std::make_unique<Table>("result", result_tbl_col_defs);
-
-	Row& new_row = table_def->create_empty_row();
-	new_row.setIntColumnValue(0, code);
-	new_row.setStringColumnValue(1, text.size() <= 48 ? text : text.substr(0,48));
-	new_row.setIntColumnValue(2, (long)affected_rows);
-	table_def->commit_row(new_row);
-
-    return table_def;
+std::unique_ptr<ValueNode> USql::to_string_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	long date = evaluatedPars[0]->getDateValue();
+	std::string format = evaluatedPars[1]->getStringValue();
+	std::string formatted_date = date_to_string(date, format);
+	return std::make_unique<StringValueNode>(formatted_date);
 }
 
+std::unique_ptr<ValueNode> USql::to_date_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	std::string date = evaluatedPars[0]->getStringValue();
+	std::string format = evaluatedPars[1]->getStringValue();
+	long epoch_time = string_to_date(date, format);
+	return std::make_unique<IntValueNode>(epoch_time);        // No DateValueNode for now
+}
 
+std::unique_ptr<ValueNode> USql::upper_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	std::string str = evaluatedPars[0]->getStringValue();
+	std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) -> unsigned char { return toupper(c); });
+	return std::make_unique<StringValueNode>(str);
+}
+
+std::unique_ptr<ValueNode> USql::lower_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	std::string str = evaluatedPars[0]->getStringValue();
+	std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c) -> unsigned char { return tolower(c); });
+	return std::make_unique<StringValueNode>(str);
+}
+
+std::unique_ptr<ValueNode> USql::pp_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	auto &parsed_value = evaluatedPars[0];
+
+	if (parsed_value->node_type == NodeType::int_value || parsed_value->node_type == NodeType::float_value) {
+		std::string format = evaluatedPars.size() > 1 ? evaluatedPars[1]->getStringValue() : "";
+		char buf[16] {0};
+		double value = parsed_value->getDoubleValue();
+
+		if (format == "100%")
+			std::snprintf(buf, 20, "%.2f%%", value);
+		else if (value >= 1000000000000)
+			std::snprintf(buf, 20, "%7.2fT", value/1000000000000);
+		else if (value >= 1000000000)
+			std::sprintf(buf, "%7.2fB", value/1000000000);
+		else if (value >= 1000000)
+			std::snprintf(buf, 20, "%7.2fM", value/1000000);
+		else if (value >= 100000)
+			std::snprintf(buf, 20, "%7.2fM", value/100000);	// 0.12M
+		else if (value <= -1000000000000)
+			std::snprintf(buf, 20, "%7.2fT", value/1000000000000);
+		else if (value <= -1000000000)
+			std::snprintf(buf, 20, "%7.2fB", value/1000000000);
+		else if (value <= -1000000)
+			std::snprintf(buf, 20, "%7.2fM", value/1000000);
+		else if (value <= -100000)
+			std::snprintf(buf, 20, "%7.2fM", value/100000);	// 0.12M
+		else if (value == 0)
+			buf[0]='0';
+		else
+			return std::make_unique<StringValueNode>(parsed_value->getStringValue().substr(0, 10));
+		// TODO introduce constant for 10
+		std::string s {buf};
+		return std::make_unique<StringValueNode>(string_padd(s.erase(s.find_last_not_of(" ")+1), 10, ' ', false));
+	}
+	return std::make_unique<StringValueNode>(parsed_value->getStringValue());
+}
+
+std::unique_ptr<ValueNode>
+USql::max_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars, const ColDefNode *col_def_node,
+		   ColValue *agg_func_value) {
+	if (col_def_node->type == ColumnType::integer_type || col_def_node->type == ColumnType::date_type) {
+		if (!evaluatedPars[0]->isNull()) {
+			long val = evaluatedPars[0]->getIntegerValue();
+			if (agg_func_value->isNull()) {
+				return std::make_unique<IntValueNode>(val);
+			} else {
+				return std::make_unique<IntValueNode>(std::max(val, agg_func_value->getIntValue()));
+			}
+		} else {
+			return std::make_unique<IntValueNode>(agg_func_value->getIntValue());
+		}
+	} else if (col_def_node->type == ColumnType::float_type) {
+		if (!evaluatedPars[0]->isNull()) {
+			double val = evaluatedPars[0]->getDoubleValue();
+			if (agg_func_value->isNull()) {
+				return std::make_unique<DoubleValueNode>(val);
+			} else {
+				return std::make_unique<DoubleValueNode>(std::max(val, agg_func_value->getDoubleValue()));
+			}
+		} else {
+			return std::make_unique<DoubleValueNode>(agg_func_value->getDoubleValue());
+		}
+	}
+
+	// TODO string and boolean
+	throw Exception("unsupported data type for max function");
+}
+
+std::unique_ptr<ValueNode>
+USql::min_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars, const ColDefNode *col_def_node,
+		   ColValue *agg_func_value) {
+	if (col_def_node->type == ColumnType::integer_type || col_def_node->type == ColumnType::date_type) {
+		if (!evaluatedPars[0]->isNull()) {
+			long val = evaluatedPars[0]->getIntegerValue();
+			if (agg_func_value->isNull()) {
+				return std::make_unique<IntValueNode>(val);
+			} else {
+				return std::make_unique<IntValueNode>(std::min(val, agg_func_value->getIntValue()));
+			}
+		} else {
+			return std::make_unique<IntValueNode>(agg_func_value->getIntValue());
+		}
+	} else if (col_def_node->type == ColumnType::float_type) {
+		if (!evaluatedPars[0]->isNull()) {
+			double val = evaluatedPars[0]->getDoubleValue();
+			if (agg_func_value->isNull()) {
+				return std::make_unique<DoubleValueNode>(val);
+			} else {
+				return std::make_unique<DoubleValueNode>(std::min(val, agg_func_value->getDoubleValue()));
+			}
+		} else {
+			return std::make_unique<DoubleValueNode>(agg_func_value->getDoubleValue());
+		}
+	}
+
+	// TODO string and boolean
+	throw Exception("unsupported data type for min function");
+}
 
 Table *USql::find_table(const std::string &name) {
 	auto name_cmp = [name](const Table& t) { return t.m_name == name; };
diff --git a/usql.h b/usql.h
index cfda794..554bb78 100644
--- a/usql.h
+++ b/usql.h
@@ -35,10 +35,10 @@ private:
 private:
     static bool eval_where(Node *where, Table *table, Row &row) ;
 
-    static std::unique_ptr<ValueNode> eval_value_node(Table *table, Row &row, Node *node);
+    static std::unique_ptr<ValueNode> eval_value_node(Table *table, Row &row, Node *node, ColDefNode *col_def_node, ColValue *agg_func_value);
     static std::unique_ptr<ValueNode> eval_database_value_node(Table *table, Row &row, Node *node);
     static std::unique_ptr<ValueNode> eval_literal_value_node(Table *table, Row &row, Node *node);
-    static std::unique_ptr<ValueNode> eval_function_value_node(Table *table, Row &row, Node *node);
+    static std::unique_ptr<ValueNode> eval_function_value_node(Table *table, Row &row, Node *node, ColDefNode *col_def_node, ColValue *agg_func_value);
 
 
     static bool eval_relational_operator(const RelationalOperatorNode &filter, Table *table, Row &row) ;
@@ -60,6 +60,22 @@ private:
     static void execute_distinct(SelectFromTableNode &node, Table *result) ;
     static void execute_order_by(SelectFromTableNode &node, Table *table, Table *result) ;
     static void execute_offset_limit(OffsetLimitNode &node, Table *result) ;
+
+    void expand_asterix_char(SelectFromTableNode &node, Table *table) const;
+
+    bool check_for_aggregate_only_functions(SelectFromTableNode &node, int result_cols_cnt) const;
+
+    static std::unique_ptr<ValueNode> lower_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
+    static std::unique_ptr<ValueNode> upper_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
+    static std::unique_ptr<ValueNode> to_date_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
+    static std::unique_ptr<ValueNode> to_string_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
+    static std::unique_ptr<ValueNode> pp_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
+
+    static std::unique_ptr<ValueNode> max_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars, const ColDefNode *col_def_node, ColValue *agg_func_value);
+    static std::unique_ptr<ValueNode> min_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars, const ColDefNode *col_def_node, ColValue *agg_func_value);
+
+    static std::unique_ptr<ValueNode>
+    count_function(ColValue *agg_func_value, const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
 };
 
 }	// namespace
\ No newline at end of file
diff --git a/usql_ddl.cpp b/usql_ddl.cpp
new file mode 100644
index 0000000..38a84d9
--- /dev/null
+++ b/usql_ddl.cpp
@@ -0,0 +1,120 @@
+#include "usql.h"
+#include "exception.h"
+#include "ml_date.h"
+#include "ml_string.h"
+
+#include <algorithm>
+#include <fstream>
+
+namespace usql {
+
+
+
+std::unique_ptr<Table> USql::execute_create_table(CreateTableNode &node) {
+	check_table_not_exists(node.table_name);
+
+	Table table{node.table_name, node.cols_defs};
+	m_tables.push_back(table);
+
+	return create_stmt_result_table(0, "table created", 0);
+}
+
+
+std::unique_ptr<Table> USql::execute_create_table_as_table(CreateTableAsSelectNode &node) {
+	check_table_not_exists(node.table_name);
+
+	auto select = execute_select((SelectFromTableNode &) *node.select_table);
+
+	// create table
+	Table new_table{node.table_name, select->m_col_defs};
+	m_tables.push_back(new_table);
+
+	// copy rows
+	// must be here, if rows are put into new_table, they are lost during m_tables.push_table
+	Table *table = find_table(node.table_name);
+	for( Row& orig_row : select->m_rows) {
+		table->commit_copy_of_row(orig_row);
+	}
+
+	select.release();	// is it correct? hoping not to release select table here and then when releasing CreateTableAsSelectNode
+
+	return create_stmt_result_table(0, "table created", table->m_rows.size());
+}
+
+
+
+std::unique_ptr<Table> USql::execute_drop(DropTableNode &node) {
+	auto name_cmp = [node](const Table& t) { return t.m_name == node.table_name; };
+
+	auto table_def = std::find_if(begin(m_tables), end(m_tables), name_cmp);
+	if (table_def != std::end(m_tables)) {
+		m_tables.erase(table_def);
+		return create_stmt_result_table(0, "drop succeeded", 0);
+	}
+
+	throw Exception("table not found (" + node.table_name + ")");
+}
+
+std::unique_ptr<Table> USql::execute_set(SetNode &node) {
+	Settings::set_setting(node.name, node.value);
+	return create_stmt_result_table(0, "set succeeded", 1);
+}
+
+std::unique_ptr<Table> USql::execute_show(ShowNode &node) {
+	std::string value = Settings::get_setting(node.name);
+	return create_stmt_result_table(0, "show succeeded: " + value, 1);
+}
+
+
+std::unique_ptr<Table> USql::create_stmt_result_table(long code, const std::string &text, size_t affected_rows) {
+	std::vector<ColDefNode> result_tbl_col_defs{};
+	result_tbl_col_defs.emplace_back("code", ColumnType::integer_type, 0, 1, false);
+	result_tbl_col_defs.emplace_back("desc", ColumnType::varchar_type, 1, 48, false);
+	result_tbl_col_defs.emplace_back("affected_rows", ColumnType::integer_type, 0, 1, true);
+
+	auto table_def = std::make_unique<Table>("result", result_tbl_col_defs);
+
+	Row& new_row = table_def->create_empty_row();
+	new_row.setIntColumnValue(0, code);
+	new_row.setStringColumnValue(1, text.size() <= 48 ? text : text.substr(0,48));
+	new_row.setIntColumnValue(2, (long)affected_rows);
+	table_def->commit_row(new_row);
+
+    return table_def;
+}
+
+
+
+std::unique_ptr<Table> USql::execute_load(LoadIntoTableNode &node) {
+	// find source table
+	Table *table_def = find_table(node.table_name);
+
+	// read data
+	// std::ifstream ifs(node.filename);
+	// std::string content((std::istreambuf_iterator<char>(ifs)), (std::istreambuf_iterator<char>()));
+	// load rows
+	// auto rows_cnt = table_def->load_csv_string(content);
+
+	auto rows_cnt = table_def->load_csv_file(node.filename);
+
+	return create_stmt_result_table(0, "load succeeded", rows_cnt);
+}
+
+
+std::unique_ptr<Table> USql::execute_save(SaveTableNode &node) {
+	// find source table
+	Table *table_def = find_table(node.table_name);
+
+	// make csv string
+	std::string csv_string = table_def->csv_string();
+
+	// save data
+	std::ofstream file(node.filename);
+	file << csv_string;
+	file.close();
+
+	return create_stmt_result_table(0, "save succeeded", table_def->rows_count());
+}
+
+
+}	// namespace
diff --git a/usql_dml.cpp b/usql_dml.cpp
new file mode 100644
index 0000000..acf2163
--- /dev/null
+++ b/usql_dml.cpp
@@ -0,0 +1,313 @@
+#include "usql.h"
+#include "exception.h"
+#include "ml_date.h"
+#include "ml_string.h"
+
+#include <algorithm>
+#include <fstream>
+
+namespace usql {
+
+
+std::unique_ptr<Table> USql::execute_select(SelectFromTableNode &node) {
+	// find source table
+	Table *table = find_table(node.table_name);
+
+	// expand *
+	expand_asterix_char(node, table);
+
+	// create result table
+	std::vector<ColDefNode> result_tbl_col_defs{};
+	std::vector<int> source_table_col_index{};
+	for (int i = 0; i < node.cols_names->size(); i++) {
+		SelectColNode * col_node = &node.cols_names->operator[](i);
+		auto [src_tbl_col_index, rst_tbl_col_def] = get_column_definition(table, col_node, i);
+
+		source_table_col_index.push_back(src_tbl_col_index);
+		result_tbl_col_defs.push_back(rst_tbl_col_def);
+	}
+
+	// check for aggregate function
+	bool aggregate_funcs = check_for_aggregate_only_functions(node, result_tbl_col_defs.size());
+
+	auto result = std::make_unique<Table>("result", result_tbl_col_defs);
+
+
+	// execute access plan
+	Row* new_row = nullptr;
+	for (auto row = begin(table->m_rows); row != end(table->m_rows); ++row) {
+		// eval where for row
+		if (eval_where(node.where.get(), table, *row)) {
+			// prepare empty row and copy column values
+			// when agregate functions in result only one row for table
+			if (!aggregate_funcs || result->rows_count()==0) {
+				new_row = &result->create_empty_row();
+			}
+
+			for (auto idx = 0; idx < result->columns_count(); idx++) {
+				auto src_table_col_idx = source_table_col_index[idx];
+
+				if (src_table_col_idx == FUNCTION_CALL) {
+					auto evaluated_value = eval_value_node(table, *row, node.cols_names->operator[](idx).value.get(), &result_tbl_col_defs[idx], &new_row->operator[](idx));
+					ValueNode *col_value = evaluated_value.get();
+
+					new_row->setColumnValue(&result_tbl_col_defs[idx], col_value);
+				} else {
+					ColValue &col_value = row->operator[](src_table_col_idx);
+					new_row->setColumnValue(&result_tbl_col_defs[idx], col_value);
+				}
+			}
+
+			// add row to result
+			if (aggregate_funcs == 0) {
+				result->commit_row(*new_row);
+			}
+		}
+	}
+	// when aggregates commit this one row
+	if (aggregate_funcs && new_row != nullptr) {
+		result->commit_row(*new_row);
+	}
+
+	execute_distinct(node, result.get());
+
+	execute_order_by(node, table, result.get());
+
+	execute_offset_limit(node.offset_limit, result.get());
+
+	return result;
+}
+
+bool USql::check_for_aggregate_only_functions(SelectFromTableNode &node, int result_cols_cnt) const {
+	int aggregate_funcs = 0;
+	for (int i = 0; i < node.cols_names->size(); i++) {
+		SelectColNode * col_node = &node.cols_names->operator[](i);
+		if (col_node->value->node_type == NodeType::function) {
+			auto func_node = static_cast<FunctionNode *>(col_node->value.get());
+			if (func_node->function == "count" || func_node->function == "min" || func_node->function == "max")
+				aggregate_funcs++;
+		}
+	}
+	// check whether aggregates are not present or all columns are aggregates
+	if (aggregate_funcs > 0 && aggregate_funcs != result_cols_cnt) {
+		throw Exception("aggregate functions with no aggregates");
+	}
+
+	return aggregate_funcs > 0;
+}
+
+void USql::expand_asterix_char(SelectFromTableNode &node, Table *table) const {
+	if (node.cols_names->size() == 1 && node.cols_names->operator[](0).name == "*") {
+		node.cols_names->clear();
+		node.cols_names->reserve(table->columns_count());
+		for(const auto& col : table->m_col_defs) {
+			node.cols_names->emplace_back(SelectColNode{std::__1::make_unique<DatabaseValueNode>(col.name), col.name});
+		}
+	}
+}
+
+void USql::execute_distinct(SelectFromTableNode &node, Table *result) {
+	if (!node.distinct) return;
+	
+	auto compare_rows = [](const Row &a, const Row &b) { return a.compare(b) >= 0; };
+	std::sort(result->m_rows.begin(), result->m_rows.end(), compare_rows);
+
+	result->m_rows.erase(std::unique(result->m_rows.begin(), result->m_rows.end()), result->m_rows.end());
+}
+
+void USql::execute_order_by(SelectFromTableNode &node, Table *table, Table *result) {
+	if (node.order_by.empty()) return;
+
+	auto compare_rows = [&node, &result](const Row &a, const Row &b) {
+		for(const auto& order_by_col_def : node.order_by) {
+			// TODO validate index
+			ColDefNode col_def = result->get_column_def(order_by_col_def.col_index - 1);
+			ColValue &a_val = a[col_def.order];
+			ColValue &b_val = b[col_def.order];
+
+			int compare = a_val.compare(b_val);
+
+			if (compare < 0) return order_by_col_def.ascending;
+			if (compare > 0) return !order_by_col_def.ascending;
+		}
+	     return false;
+	};
+
+	std::sort(result->m_rows.begin(), result->m_rows.end(), compare_rows);
+}
+
+void USql::execute_offset_limit(OffsetLimitNode &node, Table *result) {
+	if (node.offset > 0)
+		result->m_rows.erase(result->m_rows.begin(), result->rows_count() > node.offset ? result->m_rows.begin() + node.offset : result->m_rows.end());
+
+	if (node.limit > 0 && node.limit < result->rows_count())
+		result->m_rows.erase(result->m_rows.begin() + node.limit, result->m_rows.end());
+}
+
+std::tuple<int, ColDefNode> USql::get_column_definition(Table *table, SelectColNode *select_col_node, int col_order ) {
+	return get_node_definition(table, select_col_node->value.get(), select_col_node->name, col_order );
+}
+
+std::tuple<int, ColDefNode> USql::get_node_definition(Table *table, Node * node, const std::string & col_name, int col_order ) {
+	if (node->node_type == NodeType::database_value) {
+		auto dbval_node = static_cast<DatabaseValueNode *>(node);
+
+		ColDefNode src_col_def = table->get_column_def(dbval_node->col_name);
+		ColDefNode col_def = ColDefNode{col_name, src_col_def.type, col_order, src_col_def.length, src_col_def.null};
+		return std::make_tuple(src_col_def.order, col_def);
+
+	} else if (node->node_type == NodeType::function) {
+		auto func_node = static_cast<FunctionNode *>(node);
+
+		if (func_node->function == "to_string") {
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 32, true};
+			return std::make_tuple(-1, col_def);
+		} else if (func_node->function == "to_date") {
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
+			return std::make_tuple(-1, col_def);
+		} else if (func_node->function == "pp") {
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 10, true};
+			return std::make_tuple(-1, col_def);
+		} else if (func_node->function == "lower" || func_node->function == "upper") {
+			// TODO get length
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 256, true};
+			return std::make_tuple(-1, col_def);
+		} else if (func_node->function == "min" || func_node->function == "max") {
+			// TODO get correct type and length
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
+			return std::make_tuple(-1, col_def);
+		} else if (func_node->function == "count") {
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
+			return std::make_tuple(-1, col_def);
+		}
+		throw Exception("Unsupported function");
+
+	} else if (node->node_type == NodeType::arithmetical_operator) {
+		auto ari_node = static_cast<ArithmeticalOperatorNode *>(node);
+
+		auto [left_col_index, left_tbl_col_def] = get_node_definition(table, ari_node->left.get(), col_name, col_order );
+		auto [right_col_index, right_tbl_col_def] = get_node_definition(table, ari_node->right.get(), col_name, col_order );
+
+		ColumnType col_type;	// TODO handle varchar and it len
+		if (left_tbl_col_def.type==ColumnType::float_type || right_tbl_col_def.type==ColumnType::float_type)
+			col_type = ColumnType::float_type;
+		else
+			col_type = ColumnType::integer_type;
+
+		ColDefNode col_def = ColDefNode{col_name, col_type, col_order, 1, true};
+		return std::make_tuple(-1, col_def);
+
+	} else if (node->node_type == NodeType::logical_operator) {
+		ColDefNode col_def = ColDefNode{col_name, ColumnType::bool_type, col_order, 1, true};
+		return std::make_tuple(-1, col_def);
+
+	} else if (node->node_type == NodeType::int_value) {
+		ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
+		return std::make_tuple(-1, col_def);
+
+	} else if (node->node_type == NodeType::float_value) {
+		ColDefNode col_def = ColDefNode{col_name, ColumnType::float_type, col_order, 1, true};
+		return std::make_tuple(-1, col_def);
+
+	} else if (node->node_type == NodeType::string_value) {
+		// TODO right len
+		ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 64, true};
+		return std::make_tuple(-1, col_def);
+	}
+	throw Exception("Unsupported node type");
+}
+
+
+
+
+std::unique_ptr<Table> USql::execute_insert_into_table(InsertIntoTableNode &node) {
+	// find table
+	Table *table_def = find_table(node.table_name);
+
+	if (node.cols_names.size() != node.cols_values.size())
+		throw Exception("Incorrect number of values");
+
+	// prepare empty new_row
+	Row& new_row = table_def->create_empty_row();
+
+	// copy values
+	for (size_t i = 0; i < node.cols_names.size(); i++) {
+		ColDefNode col_def = table_def->get_column_def(node.cols_names[i].col_name);
+		auto col_value = eval_value_node(table_def, new_row, node.cols_values[i].get(), nullptr, nullptr);
+
+		new_row.setColumnValue(&col_def, col_value.get());
+	}
+
+	// append new_row
+	table_def->commit_row(new_row);
+
+	return create_stmt_result_table(0, "insert succeeded", 1);
+}
+
+
+
+std::unique_ptr<Table> USql::execute_delete(DeleteFromTableNode &node) {
+	// find source table
+	Table *table = find_table(node.table_name);
+
+	// execute access plan
+	auto affected_rows = table->rows_count();
+
+	table->m_rows.erase(
+		std::remove_if(table->m_rows.begin(), table->m_rows.end(), 
+				[&node, table](Row &row){return eval_where(node.where.get(), table, row);}),
+		table->m_rows.end());
+
+	affected_rows -= table->rows_count();
+
+	return create_stmt_result_table(0, "delete succeeded", affected_rows);
+}
+
+
+std::unique_ptr<Table> USql::execute_update(UpdateTableNode &node) {
+	// find source table
+	Table *table = find_table(node.table_name);
+
+	// execute access plan
+	int affected_rows = 0;
+	for (auto row = begin(table->m_rows); row != end(table->m_rows); ++row) {
+		// eval where for row
+		if (eval_where(node.where.get(), table, *row)) {
+			int i = 0;
+			for (const auto& col : node.cols_names) {
+				// TODO cache it like in select
+				ColDefNode col_def = table->get_column_def(col.col_name);
+				std::unique_ptr<ValueNode> new_val = eval_arithmetic_operator(col_def.type,
+											      static_cast<ArithmeticalOperatorNode &>(*node.values[i]),
+											      table, *row);
+
+				usql::Table::validate_column(&col_def, new_val.get());
+				row->setColumnValue(&col_def, new_val.get());
+				i++;
+			}
+			affected_rows++;
+			// TODO tady je problem, ze kdyz to zfajluje na jednom radku ostatni by se nemely provest
+		}
+	}
+
+	return create_stmt_result_table(0, "update succeeded", affected_rows);
+}
+
+
+bool USql::eval_where(Node *where, Table *table, Row &row) {
+	switch (where->node_type) {
+		case NodeType::true_node:
+			return true;
+		case NodeType::relational_operator:     //  just one condition
+			return eval_relational_operator(*((RelationalOperatorNode *) where), table, row);
+		case NodeType::logical_operator:
+			return eval_logical_operator(*((LogicalOperatorNode *) where), table, row);
+		default:
+			throw Exception("Wrong node type");
+	}
+
+	return false;
+}
+
+
+}	// namespace