Example #1
0
        private void GenerateSetOperationHelper(SetOperationBase setOperation)
        {
            _relationalCommandBuilder.AppendLine("(");
            using (_relationalCommandBuilder.Indent())
            {
                this.GenerateSetOperation(setOperation);
            }

            _relationalCommandBuilder.AppendLine()
            .Append(")")
            .Append(AliasSeparator)
            .Append(_sqlGenerationHelper.DelimitIdentifier(setOperation.Alias));
        }
Example #2
0
        protected virtual void GenerateSetOperation(SetOperationBase setOperation)
        {
            string getSetOperation() => setOperation switch
            {
                ExceptExpression _ => "EXCEPT",
                IntersectExpression _ => "INTERSECT",
                UnionExpression _ => "UNION",
                                 _ => throw new InvalidOperationException("Unknown SetOperationType."),
            };

            GenerateSetOperationOperand(setOperation, setOperation.Source1);
            _relationalCommandBuilder.AppendLine();
            _relationalCommandBuilder.AppendLine($"{getSetOperation()}{(setOperation.IsDistinct ? "" : " ALL")}");
            GenerateSetOperationOperand(setOperation, setOperation.Source2);
        }
Example #3
0
        protected virtual void GenerateSetOperationOperand(SetOperationBase setOperation, SelectExpression operand)
        {
            // INTERSECT has higher precedence over UNION and EXCEPT, but otherwise evaluation is left-to-right.
            // To preserve meaning, add parentheses whenever a set operation is nested within a different set operation.
            if (IsNonComposedSetOperation(operand) &&
                operand.Tables[0].GetType() != setOperation.GetType())
            {
                _relationalCommandBuilder.AppendLine("(");

                using (_relationalCommandBuilder.Indent())
                {
                    Visit(operand);
                }

                _relationalCommandBuilder.AppendLine().Append(")");
            }
            else
            {
                Visit(operand);
            }
        }