private void LoadQueryWithDerivedTableAndCte()
{
UnionSubQuery unionSubQuery = _query.QueryRoot.FirstSelect();
// Derived Table
SQLFromQuery fq = new SQLFromQuery(_query.SQLContext)
{
Alias = new SQLAliasObjectAlias(_query.SQLContext)
{
Alias = _query.QueryRoot.CreateUniqueSubQueryName()
},
SubQuery = new SQLSubSelectStatement(_query.SQLContext)
};
SQLSubQuerySelectExpression sqse = new SQLSubQuerySelectExpression(_query.SQLContext);
fq.SubQuery.Add(sqse);
sqse.SelectItems = new SQLSelectItems(_query.SQLContext);
sqse.From = new SQLFromClause(_query.SQLContext);
DataSourceQuery dataSourceQuery = (DataSourceQuery)_query.AddObject(unionSubQuery, fq, typeof(DataSourceQuery));
UnionSubQuery usc = dataSourceQuery.SubQuery.FirstSelect();
DataSource dsDerivedTable = _query.AddObject(usc, "MyDB.MySchema.SalesOrderHeader");
QueryColumnListItem ciDerivedTable1 = usc.QueryColumnList.AddField(dsDerivedTable, "OrderDate");
ciDerivedTable1.Selected = true;
QueryColumnListItem ciDerivedTable2 = usc.QueryColumnList.AddField(dsDerivedTable, "SalesOrderID");
ciDerivedTable2.ConditionStrings[0] = "> 25";
// CTE
SQLQualifiedName qn = new SQLQualifiedName(_query.SQLContext);
if (!unionSubQuery.QueryRoot.SQLContext.SyntaxProvider.IsSupportCTE())
{
return;
}
DataSource dataSourceCte = null;
try {
AstTokenIdentifier withClauseItemName = _query.QueryRoot.CreateUniqueCTEName("CTE");
qn.Add(withClauseItemName);
SubQuery parentSubQuery = unionSubQuery.ParentSubQuery ?? unionSubQuery.QueryRoot as SubQuery;
if (parentSubQuery.IsMainQuery)
{
_query.QueryRoot.AddNewCTE(null, withClauseItemName);
}
else
{
if (parentSubQuery.IsSubQueryCTE())
{
int index = parentSubQuery.GetSubQueryCTEIndex();
parentSubQuery.InsertNewCTE(index, null, withClauseItemName);
}
else
{
parentSubQuery.AddNewCTE(null, withClauseItemName);
}
}
if (_query.IsUniqueAlias(unionSubQuery, withClauseItemName))
{
dataSourceCte = _query.AddObject(unionSubQuery, qn, null);
}
else
{
string withClauseItemNameStr = withClauseItemName.GetSQL(new SQLGenerationOptions());
using (AstTokenIdentifier alias = _query.CreateUniqueAlias(unionSubQuery, withClauseItemNameStr)) {
dataSourceCte = _query.AddObject(unionSubQuery, qn, alias);
}
}
} finally {
qn.Dispose();
}
SubQuery cte = _query.QueryRoot.GetSubQueryCTEList().FirstOrDefault();
if (cte == null)
{
return;
}
UnionSubQuery unionSubQueryCte = cte.FirstSelect();
DataSource ds1 = _query.AddObject(unionSubQueryCte, "MyDB.MySchema.Customers");
// create output column
QueryColumnListItem ci1 = unionSubQueryCte.QueryColumnList.AddField(ds1, "CustomerName");
ci1.Selected = true;
// create output column
QueryColumnListItem ci2 = unionSubQuery.QueryColumnList.AddField(dataSourceCte, "CustomerName");
ci2.Selected = true;
}