relational operators added

executor.cpp

@@ -205,12 +205,19 @@ bool Executor::evalRelationalOperator(const RelationalOperatorNode &filter, Tabl
     }
 
 
-    if (filter.op == RelationalOperatorType::greater) {
-        return comparator > 0.0;
-    }
-
-    if (filter.op == RelationalOperatorType::equal) {
-        return comparator == 0.0;
+    switch (filter.op) {
+        case RelationalOperatorType::equal:
+            return comparator == 0.0;
+        case RelationalOperatorType::not_equal:
+            return comparator != 0.0;
+        case RelationalOperatorType::greater:
+            return comparator > 0.0;
+        case RelationalOperatorType::greater_equal:
+            return comparator >= 0.0;
+        case RelationalOperatorType::lesser:
+            return comparator < 0.0;
+        case RelationalOperatorType::lesser_equal:
+            return comparator <= 0.0;
     }
 
     throw Exception("invalid relational operator");

main.cpp

@@ -19,7 +19,8 @@ int main(int argc, char *argv[]) {
             "insert into a (i, s) values(4, 'four')",
             "select i, s from a where i > 2",
             "select i, s from a where i = 1",
-            "select i, s from a where s = 'two'"
+            "select i, s from a where s = 'two'",
+            "select i, s from a where i <= 3"
 //            "update a set s = 'three' where i = 3"
 //            "delete from a where i = 3"
 //            "select i, s from a where i > 0"

parser.cpp

@@ -170,7 +170,7 @@ std::unique_ptr<Node> Parser::parse_operand_node() {
         case TokenType::identifier:
             return std::make_unique<DatabaseValueNode>(tokenString);
         default: ;
-            // Throw exception
+            throw Exception("Unknown operand node");
     }
 }
 
@@ -179,9 +179,17 @@ RelationalOperatorType Parser::parse_operator() {
     switch (op.type) {
         case TokenType::equal:
             return RelationalOperatorType::equal;
+        case TokenType::not_equal:
+            return RelationalOperatorType::not_equal;
         case TokenType::greater:
             return RelationalOperatorType::greater;
+        case TokenType::greater_equal:
+            return RelationalOperatorType::greater_equal;
+        case TokenType::lesser:
+            return RelationalOperatorType::lesser;
+        case TokenType::lesser_equal:
+            return RelationalOperatorType::lesser_equal;
         default: ;
-            // Throw exception
+            throw Exception("Unknown relational operator");
     }
 }

parser.h

@@ -91,19 +91,26 @@ struct  DatabaseValueNode : Node {
     DatabaseValueNode(std::string name) : Node(NodeType::database_value), col_name(name) {}
 };
 
+enum class LogicalOperatorType {
+    and_operator,
+    or_operator,
+    not_operator
+};
+
 struct LogicalOperatorNode : Node {
-//    and_operator,
-//    or_operator,
-//    not_operator,
-    // and / or / not
+    LogicalOperatorType  op;
     std::unique_ptr<Node> left;
     std::unique_ptr<Node> right;
 };
 
 enum class RelationalOperatorType {
     equal,
-    greater
-    // =, !=, >, >=, <, <=, like
+    greater,
+    greater_equal,
+    lesser,
+    lesser_equal,
+    not_equal
+    // like
 };
 
 struct RelationalOperatorNode : Node {