WIP on indexes cat

Readme.md

@@ -1,11 +1,18 @@
 ### WIP
-compare in row.cpp shoud take into account m_visible
 
 ### TODO
 - create local_install.sh
 
+- change float type keyword to double and in code functions too
+
+- add functions:
+	- coalesce
+	- now
+	- rtrim, ltrim, rpad, lpad
+	- round
+
 - set xxx - without value to reset to default value
-- coalesce, date functions now; string functions rtrim, ltrim, rpad, lpad; math function round
+
 - add pipe | concatenation
 - add support for 1_000_000 numbers
 - expand_asterix_char should support multiple and everywhere *

debug.h

@@ -10,27 +10,30 @@ std::vector<std::string> k_debug_sql_commands {
 		// "delete from history_earnings_dates where symbol='BABA' and datetime=to_date('2021-11-04', '%Y-%m-%d')",
 		// "select * from history_earnings_dates"
 
-		//  "create table sf1 (symbol varchar(8) not null, dimension varchar(3), calendar_date date, date_key date, report_period date, last_updated date, accoci float, assets float, assetsavg float, assetsc float, assetsnc float, assetturnover float, bvps float, capex float, cashneq float, cashnequsd float, cor float, consolinc float, currentratio float, de float, debt float, debtc float, debtnc float, debtusd float, deferredrev float, depamor float, deposits float, divyield float, dps float, ebit float, ebitda float, ebitdamargin float, ebitdausd float, ebitusd float, ebt float, eps float, epsdil float, epsusd float, equity float, equityavg float, equityusd float, ev float, evebit float, evebitda float, fcf float, fcfps float, fxusd float, gp float, grossmargin float, intangibles float, intexp float, invcap float, invcapavg float, inventory float, investments float, investmentsc float, investmentsnc float, liabilities float, liabilitiesc float, liabilitiesnc float, marketcap float, ncf float, ncfbus float, ncfcommon float, ncfdebt float, ncfdiv float, ncff float, ncfi float, ncfinv float, ncfo float, ncfx float, netinc float, netinccmn float, netinccmnusd float, netincdis float, netincnci float, netmargin float, opex float, opinc float, payables float, payoutratio float, pb float, pe float, pe1 float, ppnenet float, prefdivis float, price float, ps float, ps1 float, receivables float, retearn float, revenue float, revenueusd float, rnd float, roa float, roe float, roic float, ros float, sbcomp float, sgna float, sharefactor float, sharesbas float, shareswa float, shareswadil float, sps float, tangibles float, taxassets float, taxexp float, taxliabilities float, tbvps float, workingcapital float)",
+		 "create table sf1 (symbol varchar(8) not null, dimension varchar(3), calendar_date date, date_key date, report_period date, last_updated date, accoci float, assets float, assetsavg float, assetsc float, assetsnc float, assetturnover float, bvps float, capex float, cashneq float, cashnequsd float, cor float, consolinc float, currentratio float, de float, debt float, debtc float, debtnc float, debtusd float, deferredrev float, depamor float, deposits float, divyield float, dps float, ebit float, ebitda float, ebitdamargin float, ebitdausd float, ebitusd float, ebt float, eps float, epsdil float, epsusd float, equity float, equityavg float, equityusd float, ev float, evebit float, evebitda float, fcf float, fcfps float, fxusd float, gp float, grossmargin float, intangibles float, intexp float, invcap float, invcapavg float, inventory float, investments float, investmentsc float, investmentsnc float, liabilities float, liabilitiesc float, liabilitiesnc float, marketcap float, ncf float, ncfbus float, ncfcommon float, ncfdebt float, ncfdiv float, ncff float, ncfi float, ncfinv float, ncfo float, ncfx float, netinc float, netinccmn float, netinccmnusd float, netincdis float, netincnci float, netmargin float, opex float, opinc float, payables float, payoutratio float, pb float, pe float, pe1 float, ppnenet float, prefdivis float, price float, ps float, ps1 float, receivables float, retearn float, revenue float, revenueusd float, rnd float, roa float, roe float, roic float, ros float, sbcomp float, sgna float, sharefactor float, sharesbas float, shareswa float, shareswadil float, sps float, tangibles float, taxassets float, taxexp float, taxliabilities float, tbvps float, workingcapital float)",
-		//  "set 'DATE_FORMAT' = '%Y-%m-%d'",
+		 "set 'DATE_FORMAT' = '%Y-%m-%d'",
-		//  "create index sf1_symbol on sf1(symbol)",
+		 "create index sf1_symbol on sf1(symbol)",
-		//  "load into sf1 '/srv/SHARADAR_SF1.csv'",
+		 "load into sf1 '/srv/SHARADAR_SF1.csv'",
+		// "set 'USE_INDEXSCAN' = 'true'",
+		 "select distinct dimension from sf1 where symbol = 'ALLY'",
+		 "select calendar_date, calendar_date, dimension from sf1 where symbol = 'ALLY' and dimension = 'MRQ' and calendar_date <= 1653487723 order by calendar_date desc limit 10",
 		//  "set 'USE_INDEXSCAN' = 'false'",
-		//  "select dimension, to_string(calendar_date, '%d.%m.%Y'), pp(eps, \"%.2f\"), pp(shareswadil), pp(revenue), pp(netinc), pp(cashneq), pp(assets), pp(debt), pp(ncfdebt), pp(roe*100), pp(intangibles), calendar_date from sf1 where symbol = 'MU' and dimension = 'ARQ' order by dimension, calendar_date desc limit 5",
+		//  "select dimension, to_char(calendar_date, '%d.%m.%Y'), pp(eps, \"%.2f\"), pp(shareswadil), pp(revenue), pp(netinc), pp(cashneq), pp(assets), pp(debt), pp(ncfdebt), pp(roe*100), pp(intangibles), calendar_date from sf1 where symbol = 'MU' and dimension = 'ARQ' order by dimension, calendar_date desc limit 5",
 		//  "set 'USE_INDEXSCAN' = 'true'",
-		//  "select dimension, to_string(calendar_date, '%d.%m.%Y'), pp(eps, \"%.2f\"), pp(shareswadil), pp(revenue), pp(netinc), pp(cashneq), pp(assets), pp(debt), pp(ncfdebt), pp(roe*100), pp(intangibles), calendar_date from sf1 where symbol = 'MU' and dimension = 'ARQ' order by dimension, calendar_date desc limit 5",
+		//  "select dimension, to_char(calendar_date, '%d.%m.%Y'), pp(eps, \"%.2f\"), pp(shareswadil), pp(revenue), pp(netinc), pp(cashneq), pp(assets), pp(debt), pp(ncfdebt), pp(roe*100), pp(intangibles), calendar_date from sf1 where symbol = 'MU' and dimension = 'ARQ' order by dimension, calendar_date desc limit 5",
 		//  "select max(calendar_date), calendar_date from sf1 where symbol = 'MU' and dimension = 'ARQ'",
 		//  "select max(calendar_date), min(calendar_date) from sf1 where symbol = 'MU' and dimension = 'ARQ'"
 
-		"create table a (i integer not null, s varchar(64))",
+		// "create table a (i integer not null, s varchar(64))",
-		"create index a_i on a(i)",
+		// "create index a_i on a(i)",
 		// "insert into a (i, s) values(1, 'one')",
 		// "insert into a (i, s) values(2, 'two')",
 		// "insert into a (i, s) values(2, 'second two')",
 		// "insert into a (i, s) values(3, 'three')",
 		// "insert into a (i, s) values(4, 'four')",
-		"insert into a (i) values(5)",
+		// "insert into a (i) values(5)",
-		"save a into '/tmp/a.csv'",
+		// "save a into '/tmp/a.csv'",
-		"set 'USE_INDEXSCAN' = 'true'",
+		// "set 'USE_INDEXSCAN' = 'true'",
 		// "select * from a where 1 = i",
 		// "delete from a where i = 2 and s ='two'",
 		// "select * from a where i = 2",
@@ -40,6 +43,21 @@ std::vector<std::string> k_debug_sql_commands {
 		// "select min(i), max(i), count(i) from a",
 		// "select i + 1000 from a",
 		// "select i, s from a where i = 5",
-		"select i, s, coalesce(s, i) from a where i = 5"
+		// "select i, s, coalesce(s, i) from a where i = 5",
+
+		// "create table a (i float, j float)",
+		// "insert into a (i, j) values(null, 123456789.12345)",
+		// "select pp(coalesce(i, j)) from a",
+
+		// "create table d (datetime date)",
+		// "insert into d (datetime) values(1648634993)",
+		// "select to_char(datetime, '%Y%m%d') from d",
+		// "select to_int(datetime) from d",
+		// "select max(to_char(datetime, '%Y%m%d')) from d",
+		// "select max(to_int(to_float(to_char(datetime, '%Y%m%d')))) from d",
+
+		// "select * from usql_tables",
+		// "select * from usql_columns",
+		// "select * from usql_indexes",
 };
 

lexer.cpp

@@ -162,7 +162,7 @@ TokenType Lexer::type(const std::string &token) {
 	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 == "float" || token == "double") 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;

parser.cpp

@@ -385,19 +385,18 @@ namespace usql {
 
     
     std::unique_ptr<Node> Parser::parse_where_clause() {
-	if (m_lexer.tokenType() != TokenType::keyword_where) {
+		if (m_lexer.tokenType() != TokenType::keyword_where) {
-		return std::make_unique<TrueNode>();
+			return std::make_unique<TrueNode>();
-	}
+		}
 
-	m_lexer.skipToken(TokenType::keyword_where);
+		m_lexer.skipToken(TokenType::keyword_where);
 
-	std::unique_ptr<Node> left = parse_expression();
+		std::unique_ptr<Node> left = parse_expression();
-	do {
+		do {
-		left = parse_expression(std::move(left));
+			left = parse_expression(std::move(left));
-
+		} while (m_lexer.tokenType() != TokenType::eof && m_lexer.tokenType() != TokenType::keyword_order && m_lexer.tokenType() != TokenType::keyword_offset && m_lexer.tokenType() != TokenType::keyword_limit && m_lexer.tokenType() != TokenType::semicolon);
-	} while (m_lexer.tokenType() != TokenType::eof && m_lexer.tokenType() != TokenType::keyword_order && m_lexer.tokenType() != TokenType::keyword_offset && m_lexer.tokenType() != TokenType::keyword_limit);
 	
-	return left;
+		return left;
     }
 
     std::unique_ptr<Node> Parser::parse_expression() {

parser.h

@@ -126,8 +126,10 @@ struct ColDefNode : Node {
 struct FunctionNode : Node {
 
 	enum class Type {
-		to_string,
+		to_char,
 		to_date,
+		to_int,
+		to_float,
 		date_add,
 		pp,
 		lower,
@@ -139,13 +141,15 @@ struct FunctionNode : Node {
 	};
 
 	static Type get_function(const std::string &str) {
-		if (str=="to_string")	return Type::to_string;
+		if (str=="to_char")		return Type::to_char;
 		if (str=="to_date")		return Type::to_date;
+		if (str=="to_int")		return Type::to_int;
+		if (str=="to_float")	return Type::to_float;
 		if (str=="date_add")	return Type::date_add;
 		if (str=="pp")			return Type::pp;
 		if (str=="lower")		return Type::lower;
 		if (str=="upper")		return Type::upper;
-		if (str=="coalesce")		return Type::coalesce;
+		if (str=="coalesce")	return Type::coalesce;
 		if (str=="min")			return Type::min;
 		if (str=="max")			return Type::max;
 		if (str=="count")		return Type::count;
@@ -154,8 +158,10 @@ struct FunctionNode : Node {
 	};
 
 	static std::string function_name(const Type type) {
-		if (type == Type::to_string)	return "to_string";
+		if (type == Type::to_char)		return "to_char";
 		if (type == Type::to_date)		return "to_date";
+		if (type == Type::to_int)		return "to_int";
+		if (type == Type::to_float)		return "to_float";
 		if (type == Type::date_add)		return "date_add";
 		if (type == Type::pp)			return "pp";
 		if (type == Type::lower)		return "lower";
@@ -169,9 +175,6 @@ struct FunctionNode : Node {
 	};
 
 
-	Type					function;
-	std::vector<std::unique_ptr<Node>>	params;
-
 	FunctionNode(std::string  func_name, std::vector<std::unique_ptr<Node>> pars) :
 	Node(NodeType::function), function(get_function(func_name)), params(std::move(pars)) {}
 
@@ -193,6 +196,9 @@ struct FunctionNode : Node {
 		}			
 		std::cout << ")" << std::endl;
 	}
+
+	Type								function;
+	std::vector<std::unique_ptr<Node>>	params;
 };
 
 struct TrueNode : Node {
@@ -575,7 +581,6 @@ struct CreateIndexNode : Node {
 };
 
 class Parser {
-private:
 public:
 	Parser();
 

row.h

@@ -171,7 +171,7 @@ public:
 			case 5:
 				return (ColValue &) *std::get_if<ColBooleanValue>(&m_columns[i]);
 			default:
-				throw Exception("should not happen");
+				throw Exception("ColValue &operator[](int i), type index invalid :" + std::to_string(type_index));
 		}
 	}
 

settings.cpp

@@ -12,7 +12,7 @@ std::vector<std::pair<std::string, std::string>> Settings::m_settings =
 	      std::make_pair("BOOL_TRUE_LITERAL", "Y"),
 	      std::make_pair("BOOL_FALSE_LITERAL", "N"),
           std::make_pair("DOUBLE_FORMAT", "%.2f"),
-	      std::make_pair("USE_INDEXSCAN", "N"),
+	      std::make_pair("USE_INDEXSCAN", "Y"),
 	      std::make_pair("MAX_PARALLELISM", "1") };		// values "AUTO" or number of workers; when number negative means std::thread::hardware_concurrency() - number 
 
 

usql.cpp

@@ -6,9 +6,37 @@
 
 namespace usql {
 
+USql::USql() {
+	// create catalogue tables first
+
+	std::vector<std::string> k_debug_sql_commands {
+		"create table usql_tables(name varchar(32) not null, modified boolean not null)",
+		"create table usql_columns(table_name varchar(32) not null, column_name varchar(32) not null, column_type varchar(16) not null, column_length integer not null, nullable boolean not null, column_order integer not null)",
+		"create table usql_indexes(index_name varchar(32) not null, table_name varchar(32), column_name varchar(32) not null)"
+	};
+
+	// create cataloque tables
+	for (const auto &command : k_debug_sql_commands) {
+		std::unique_ptr<Node> create_table_node = m_parser.parse(command);
+		const CreateTableNode &node = static_cast<CreateTableNode &>(*create_table_node); 
+
+		Table table{node.table_name, node.cols_defs};
+		m_tables.push_back(table);
+
+	}
+	// insert data into cataloque tables
+	for (const auto &command : k_debug_sql_commands) {
+		std::unique_ptr<Node> create_table_node = m_parser.parse(command);
+		const CreateTableNode &node = static_cast<CreateTableNode &>(*create_table_node); 
+
+		execute_create_table_sys_catalogue(node);
+	}
+}
+
 std::unique_ptr<Table> USql::execute(const std::string &command) {
 	try {
 		std::unique_ptr<Node> node = m_parser.parse(command);
+		// node->dump();
 		return execute(*node);
 
 	} catch (const std::exception &e) {
@@ -182,7 +210,9 @@ std::unique_ptr<ValueNode> USql::eval_function_value_node(Table *table, Row &row
 	if (fnc->function == FunctionNode::Type::lower) return lower_function(evaluatedPars);
 	if (fnc->function == FunctionNode::Type::upper) return upper_function(evaluatedPars);
 	if (fnc->function == FunctionNode::Type::to_date) return to_date_function(evaluatedPars);
-	if (fnc->function == FunctionNode::Type::to_string) return to_string_function(evaluatedPars);
+	if (fnc->function == FunctionNode::Type::to_char) return to_char_function(evaluatedPars);
+	if (fnc->function == FunctionNode::Type::to_int) return to_int_function(evaluatedPars);
+	if (fnc->function == FunctionNode::Type::to_float) return to_float_function(evaluatedPars);
 	if (fnc->function == FunctionNode::Type::date_add) return date_add_function(evaluatedPars);
 	if (fnc->function == FunctionNode::Type::pp) return pp_function(evaluatedPars);
 	if (fnc->function == FunctionNode::Type::count) return count_function(agg_func_value, evaluatedPars);

usql.h

@@ -11,17 +11,18 @@
 namespace usql {
 
 class USql {
-
+	
 public:
-    USql() = default;
+	USql();
-
     std::unique_ptr<Table> execute(const std::string &command);
 
 private:
     std::unique_ptr<Table> execute(Node &node);
 
     std::unique_ptr<Table> execute_create_table(const CreateTableNode &node);
+	bool execute_create_table_sys_catalogue(const CreateTableNode &node);
     std::unique_ptr<Table> execute_create_index(const CreateIndexNode &node);
+	bool execute_create_index_sys_catalogue(const CreateIndexNode &node);
     std::unique_ptr<Table> execute_create_table_as_table(const CreateTableAsSelectNode &node);
     std::unique_ptr<Table> execute_load(const LoadIntoTableNode &node);
     std::unique_ptr<Table> execute_save(const SaveTableNode &node);
@@ -59,9 +60,6 @@ private:
 	void check_index_not_exists(const std::string &index_name);
 
 private:
-    Parser m_parser;
-    std::list<Table> m_tables;
-
     static void execute_distinct(SelectFromTableNode &node, Table *result);
     static void execute_order_by(SelectFromTableNode &node, Table *result);
     static void execute_offset_limit(OffsetLimitNode &node, Table *result);
@@ -75,7 +73,9 @@ private:
     static std::unique_ptr<ValueNode> upper_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
     static std::unique_ptr<ValueNode> coalesce_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> to_char_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
+    static std::unique_ptr<ValueNode> to_int_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
+    static std::unique_ptr<ValueNode> to_float_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
     static std::unique_ptr<ValueNode> date_add_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
     static std::unique_ptr<ValueNode> pp_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars);
 
@@ -95,6 +95,11 @@ private:
 	bool normalize_where(const Node *node) const;
 
     Table::rows_scanner get_iterator(Table *table, const Node *where) const;
+
+
+private:
+    Parser m_parser;
+    std::list<Table> m_tables;
 };
 
 

usql_ddl.cpp

@@ -8,17 +8,41 @@
 namespace usql {
 
 
-
 std::unique_ptr<Table> USql::execute_create_table(const CreateTableNode &node) {
 	check_table_not_exists(node.table_name);
 
 	Table table{node.table_name, node.cols_defs};
 	m_tables.push_back(table);
 
+	execute_create_table_sys_catalogue(node);
+
 	return create_stmt_result_table(0, "table created", 0);
 }
 
 
+bool USql::execute_create_table_sys_catalogue(const CreateTableNode &node) {
+	// usql_tables 
+	auto r = execute("insert into usql_tables(name, modified) values('" + node.table_name + "', false)");
+
+	// usql_columns 
+	for(const ColDefNode & col_def : node.cols_defs) {
+		std::string i {"insert into usql_columns(table_name, column_name, column_type, column_length, nullable, column_order) values("};
+					i += "'" + node.table_name + "', ";
+					i += "'" + col_def.name + "', ";
+					i += "'" + column_type_name(col_def.type) + "', ";
+					i += std::to_string(col_def.length) + ", ";
+					i += (col_def.null ?  "true, " : "false, ");
+					i += std::to_string(col_def.order);
+					i += ")";
+
+		auto r = execute(i);
+		// r->print();
+	}
+
+	return true;
+}
+
+
 std::unique_ptr<Table> USql::execute_create_index(const CreateIndexNode &node) {
 	Table *table_def = find_table(node.table_name);				// throws exception if not found
 	ColDefNode col_def = table_def->get_column_def(node.column_name);	// throws exception if not found
@@ -31,10 +55,25 @@ std::unique_ptr<Table> USql::execute_create_index(const CreateIndexNode &node) {
 
 	table_def->index_rows(node.index_name);
 
+	execute_create_index_sys_catalogue(node);
+
 	return create_stmt_result_table(0, "index created", 0);
 }
 
 
+bool USql::execute_create_index_sys_catalogue(const CreateIndexNode &node) {
+	std::string i {"insert into usql_indexes(index_name, table_name, column_name) values("};
+				i += "'" + node.index_name + "', ";
+				i += "'" + node.table_name + "', ";
+				i += "'" + node.column_name + "')";
+
+	auto r = execute(i);
+	// r->print();
+
+	return true;
+}
+
+
 std::unique_ptr<Table> USql::execute_create_table_as_table(const CreateTableAsSelectNode &node) {
 	check_table_not_exists(node.table_name);
 
@@ -57,7 +96,6 @@ std::unique_ptr<Table> USql::execute_create_table_as_table(const CreateTableAsSe
 }
 
 
-
 std::unique_ptr<Table> USql::execute_drop(const DropTableNode &node) {
 	auto name_cmp = [node](const Table& t) { return t.m_name == node.table_name; };
 
@@ -70,11 +108,13 @@ std::unique_ptr<Table> USql::execute_drop(const DropTableNode &node) {
 	throw Exception("table not found (" + node.table_name + ")");
 }
 
+
 std::unique_ptr<Table> USql::execute_set(const 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(const ShowNode &node) {
 	std::string value = Settings::get_setting(node.name);
 	return create_stmt_result_table(0, "show succeeded: " + value, 1);

usql_dml.cpp

@@ -35,7 +35,7 @@ std::pair<bool, std::vector<rowid_t>> USql::look_for_usable_index(const Node *wh
 					if (used_index != nullptr) {
 						std::vector<rowid_t> rowids = used_index->search((ValueNode *)ron->right.get());
 #ifndef NDEBUG
-						std::cout << "using index " << table->m_name << "(" << used_index->get_column_name() << "), " << rowids.size() << "/" << table->rows_count()  << std::endl;
+						std::cerr << "using index " << table->m_name << "(" << used_index->get_column_name() << "), " << rowids.size() << "/" << table->rows_count()  << std::endl;
 #endif
 						return std::make_pair(true, rowids);
 					}
@@ -155,8 +155,7 @@ void USql::setup_order_columns(std::vector<ColOrderNode> &node, Table *table) {
 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(), [](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());
 }
@@ -217,7 +216,7 @@ ColDefNode USql::get_db_column_definition(Table *table, Node *node) {
 	throw Exception("Undefined table node - get_db_column_definition");
 }
 
-std::tuple<int, ColDefNode> USql::get_node_definition(Table *table, Node * node, const std::string & col_name, int 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) {
 		ColDefNode src_col_def = get_db_column_definition(table, node);
 		ColDefNode col_def = ColDefNode{col_name, src_col_def.type, col_order, src_col_def.length, src_col_def.null};
@@ -226,9 +225,15 @@ std::tuple<int, ColDefNode> USql::get_node_definition(Table *table, Node * node,
 	} else if (node->node_type == NodeType::function) {
 		auto func_node = static_cast<FunctionNode *>(node);
 
-		if (func_node->function == FunctionNode::Type::to_string) {
+		if (func_node->function == FunctionNode::Type::to_char) {
 			ColDefNode col_def = ColDefNode{col_name, ColumnType::varchar_type, col_order, 32, true};
 			return std::make_tuple(FUNCTION_CALL, col_def);
+		} else if (func_node->function == FunctionNode::Type::to_int) {
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
+			return std::make_tuple(FUNCTION_CALL, col_def);
+		} else if (func_node->function == FunctionNode::Type::to_float) {
+			ColDefNode col_def = ColDefNode{col_name, ColumnType::float_type, col_order, 1, true};
+			return std::make_tuple(FUNCTION_CALL, col_def);
 		} else if (func_node->function == FunctionNode::Type::to_date) {
 			ColDefNode col_def = ColDefNode{col_name, ColumnType::integer_type, col_order, 1, true};
 			return std::make_tuple(FUNCTION_CALL, col_def);
@@ -243,18 +248,26 @@ std::tuple<int, ColDefNode> USql::get_node_definition(Table *table, Node * node,
 			// TODO handle cases here
 			if (func_node->params.empty()) throw Exception("Coalesce without parameters");
 			if (func_node->params[0]->node_type != NodeType::database_value) throw Exception("Coalesce first parameter must be database column");
+
 			ColDefNode tbl_col_def = get_db_column_definition(table, func_node->params[0].get());
 			ColDefNode col_def = ColDefNode{col_name, tbl_col_def.type, col_order, tbl_col_def.length, true};
 			return std::make_tuple(FUNCTION_CALL, col_def);
 		} else if (func_node->function == FunctionNode::Type::min || func_node->function == FunctionNode::Type::max) {
-			auto col_type= ColumnType::float_type;
+			auto col_type = ColumnType::float_type;
 			size_t col_len = 1;
-			auto & v = func_node->params[0];
+			auto &v = func_node->params[0];
+
 			if (v->node_type == NodeType::database_value) {
 				ColDefNode src_col_def = get_db_column_definition(table, v.get());
 				col_type = src_col_def.type;
 				col_len = src_col_def.length;
+
+			} else if (node->node_type == NodeType::function) {
+				std::tuple<int, ColDefNode> fun_type = get_node_definition(table, static_cast<Node*>(& *v), "", 0);
+				col_type = std::get<1>(fun_type).type;
+				col_len = std::get<1>(fun_type).length;
 			}
+
 			ColDefNode col_def = ColDefNode{col_name, col_type, col_order, col_len, true};
 			return std::make_tuple(FUNCTION_CALL, col_def);
 		} else if (func_node->function == FunctionNode::Type::count) {

usql_function.cpp

@@ -7,12 +7,24 @@
 
 namespace usql {
 
-std::unique_ptr<ValueNode> USql::to_string_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+std::unique_ptr<ValueNode> USql::to_char_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
-	long date = evaluatedPars[0]->getDateValue();
+	if (evaluatedPars[0]->node_type == NodeType::int_value && evaluatedPars.size()==2) {		// TODO when propper date is introduced
-	std::string format = evaluatedPars[1]->getStringValue();
+		long date = evaluatedPars[0]->getDateValue();
-	std::string formatted_date = date_to_string(date, format);
+		std::string format = evaluatedPars[1]->getStringValue();
+		std::string formatted_date = date_to_string(date, format);
 	
-	return std::make_unique<StringValueNode>(formatted_date);
+		return std::make_unique<StringValueNode>(formatted_date);
+	} else {
+		return std::make_unique<StringValueNode>(evaluatedPars[0]->getStringValue());
+	}
+}
+
+std::unique_ptr<ValueNode> USql::to_int_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	return std::make_unique<IntValueNode>(evaluatedPars[0]->getIntegerValue());
+}
+
+std::unique_ptr<ValueNode> USql::to_float_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {
+	return std::make_unique<DoubleValueNode>(evaluatedPars[0]->getDoubleValue());
 }
 
 std::unique_ptr<ValueNode> USql::to_date_function(const std::vector<std::unique_ptr<ValueNode>> &evaluatedPars) {