/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override void GenerateSetOperationOperand(SetOperationBase setOperation, SelectExpression operand)
{
Check.NotNull(setOperation, nameof(setOperation));
Check.NotNull(operand, nameof(operand));
// Sqlite doesn't support parentheses around set operation operands
Visit(operand);
}
/// <summary>
/// Generates a set operation in the relational command.
/// </summary>
/// <param name="setOperation"> A set operation to print. </param>
protected virtual void GenerateSetOperation([NotNull] SetOperationBase setOperation)
{
Check.NotNull(setOperation, nameof(setOperation));
GenerateSetOperationOperand(setOperation, setOperation.Source1);
_relationalCommandBuilder.AppendLine();
_relationalCommandBuilder.AppendLine($"{GetSetOperation(setOperation)}{(setOperation.IsDistinct ? "" : " ALL")}");
GenerateSetOperationOperand(setOperation, setOperation.Source2);
private void GenerateSetOperationHelper(SetOperationBase setOperation)
{
_relationalCommandBuilder.AppendLine("(");
using (_relationalCommandBuilder.Indent())
{
GenerateSetOperation(setOperation);
}
_relationalCommandBuilder.AppendLine()
.Append(")")
.Append(AliasSeparator)
.Append(_sqlGenerationHelper.DelimitIdentifier(setOperation.Alias));
}
protected virtual void GenerateSetOperation(SetOperationBase setOperation)
{
string getSetOperation() => setOperation switch
{
ExceptExpression _ => "EXCEPT",
IntersectExpression _ => "INTERSECT",
UnionExpression _ => "UNION",
_ => throw new InvalidOperationException("Unknown SetOperationType."),
};
GenerateSetOperationOperand(setOperation, setOperation.Source1);
_relationalCommandBuilder.AppendLine();
_relationalCommandBuilder.AppendLine($"{getSetOperation()}{(setOperation.IsDistinct ? "" : " ALL")}");
GenerateSetOperationOperand(setOperation, setOperation.Source2);
}
protected virtual void GenerateSetOperation([NotNull] SetOperationBase setOperation)
{
Check.NotNull(setOperation, nameof(setOperation));
string getSetOperation() => setOperation switch
{
ExceptExpression _ => "EXCEPT",
IntersectExpression _ => "INTERSECT",
UnionExpression _ => "UNION",
_ => throw new InvalidOperationException(CoreStrings.UnknownEntity("SetOperationType")),
};
GenerateSetOperationOperand(setOperation, setOperation.Source1);
_relationalCommandBuilder.AppendLine();
_relationalCommandBuilder.AppendLine($"{getSetOperation()}{(setOperation.IsDistinct ? "" : " ALL")}");
GenerateSetOperationOperand(setOperation, setOperation.Source2);
}
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);
}
}
//from ef core
private static bool IsNonComposedSetOperation(SelectExpression selectExpression)
{
if (selectExpression.Offset == null && selectExpression.Limit == null && !selectExpression.IsDistinct && selectExpression.Predicate == null && selectExpression.Having == null && selectExpression.Orderings.Count == 0 && selectExpression.GroupBy.Count == 0 && selectExpression.Tables.Count == 1)
{
TableExpressionBase tableExpressionBase = selectExpression.Tables[0];
SetOperationBase setOperation = tableExpressionBase as SetOperationBase;
if (setOperation != null && selectExpression.Projection.Count == setOperation.Source1.Projection.Count)
{
return(selectExpression.Projection.Select(delegate(ProjectionExpression pe, int index)
{
ColumnExpression columnExpression = pe.Expression as ColumnExpression;
if (columnExpression != null && string.Equals(columnExpression.Table.Alias, setOperation.Alias, StringComparison.OrdinalIgnoreCase))
{
return string.Equals(columnExpression.Name, setOperation.Source1.Projection[index].Alias, StringComparison.OrdinalIgnoreCase);
}
return false;
}).All((bool e) => e));
}
}
return(false);
}
public void P_GenerateSetOperation(SetOperationBase setOperation)
{
this.GenerateSetOperation(setOperation);
}
static string GetSetOperation(SetOperationBase operation) => operation switch
{
protected override void GenerateSetOperationOperand(SetOperationBase setOperation, SelectExpression operand)
{
// Sqlite doesn't support parentheses around set operation operands
Visit(operand);
}
