public void BuildSetOperationCombinedStatementsPart_UnionAll()
{
var setOperationCombinedStatement = new SetOperationCombinedStatement(SqlStatementModelObjectMother.CreateSqlStatement(), SetOperation.UnionAll);
var sqlStatement = SqlStatementModelObjectMother.CreateMinimalSqlStatement(
new SqlStatementBuilder
{
SetOperationCombinedStatements = { setOperationCombinedStatement }
});
_stageMock.Expect(mock => mock.GenerateTextForSqlStatement(_commandBuilder, setOperationCombinedStatement.SqlStatement))
.WhenCalled(mi => ((SqlCommandBuilder)mi.Arguments[0]).Append("statement"));
_stageMock.Replay();
_generator.BuildSetOperationCombinedStatementsPart(sqlStatement, _commandBuilder);
Assert.That(_commandBuilder.GetCommandText(), Is.EqualTo(" UNION ALL (statement)"));
_stageMock.VerifyAllExpectations();
}
public override void HandleResultOperator(
TResultOperator resultOperator,
SqlStatementBuilder sqlStatementBuilder,
UniqueIdentifierGenerator generator,
ISqlPreparationStage stage,
ISqlPreparationContext context)
{
ArgumentUtility.CheckNotNull("resultOperator", resultOperator);
ArgumentUtility.CheckNotNull("sqlStatementBuilder", sqlStatementBuilder);
ArgumentUtility.CheckNotNull("generator", generator);
ArgumentUtility.CheckNotNull("stage", stage);
ArgumentUtility.CheckNotNull("context", context);
UpdateDataInfo(resultOperator, sqlStatementBuilder, sqlStatementBuilder.DataInfo);
var source2 = GetSource2(resultOperator);
var preparedSubStatement = stage.PrepareResultOperatorItemExpression(source2, context) as SqlSubStatementExpression;
if (preparedSubStatement == null)
{
var message = string.Format(
"The '" + _operationName + "' operation is only supported for combining two query results, but a '{0}' was supplied as the "
+ "second sequence: {1}",
source2.GetType().Name,
source2);
throw new NotSupportedException(message);
}
var combinedStatement = new SetOperationCombinedStatement(preparedSubStatement.SqlStatement, _setOperation);
sqlStatementBuilder.SetOperationCombinedStatements.Add(combinedStatement);
// The set operators act as an IQuerySource, i.e., subsequent result operators can refer to its output.
// When a result operator references the set operator's output, it should simply refer to the outer statement's select projection instead.
AddMappingForItemExpression(context, sqlStatementBuilder.DataInfo, sqlStatementBuilder.SelectProjection);
// In SQL, the set operators does not allow the input sequences to contain an "ORDER BY". Therefore, we'll remove them, if any, unless a TOP
// expression is specified.
if (sqlStatementBuilder.Orderings.Any() && sqlStatementBuilder.TopExpression == null)
{
sqlStatementBuilder.Orderings.Clear();
}
// For the second source, removal of unneeded orderings is already performed by PrepareResultOperatorItemExpression.
Assertion.DebugAssert(!combinedStatement.SqlStatement.Orderings.Any() || combinedStatement.SqlStatement.TopExpression != null);
// However, if an ORDER BY _is_ included together with a TOP, then the ORDER BY is allowed again as long as the whole set-combined statement is
// moved to a substatement.
// I.e., this is invalid:
// SELECT [t0].[ID] AS [value] FROM [CookTable] AS [t0] WHERE ([t0].[FirstName] = 'Hugo')
// UNION (SELECT TOP (2) [t1].[ID] AS [value] FROM [CookTable] AS [t1] WHERE ([t1].[Name] = 'Boss') ORDER BY [t1].[ID] ASC)
// but this is valid:
// SELECT * FROM
// (
// SELECT [t0].[ID] AS [value] FROM [CookTable] AS [t0] WHERE ([t0].[FirstName] = 'Hugo')
// UNION (SELECT TOP (2) [t1].[ID] AS [value] FROM [CookTable] AS [t1] WHERE ([t1].[Name] = 'Boss') ORDER BY [t1].[ID] ASC)
// ) AS q0
if (sqlStatementBuilder.Orderings.Any() || combinedStatement.SqlStatement.Orderings.Any())
{
MoveCurrentStatementToSqlTable(
sqlStatementBuilder,
context,
ti => new SqlTable(ti, JoinSemantics.Inner),
stage,
OrderingExtractionPolicy.DoNotExtractOrderings);
}
}
