internal override SqlRowNumber VisitRowNumber(SqlRowNumber rowNumber)
{
if (rowNumber.OrderBy.Count > 0)
{
return(rowNumber);
}
SqlDuplicator dup = new SqlDuplicator(true);
List <SqlOrderExpression> orderBy = new List <SqlOrderExpression>();
List <SqlOrderExpression> existingOrders = new List <SqlOrderExpression>();
if (this.rowNumberOrders != null && this.rowNumberOrders.Count != 0)
{
existingOrders = new List <SqlOrderExpression>(this.rowNumberOrders);
}
else if (this.orders != null)
{
existingOrders = new List <SqlOrderExpression>(this.orders);
}
foreach (SqlOrderExpression expr in existingOrders)
{
if (!expr.Expression.IsConstantColumn)
{
orderBy.Add(expr);
if (this.rowNumberOrders != null)
{
this.rowNumberOrders.Remove(expr);
}
if (this.orders != null)
{
this.orders.Remove(expr);
}
}
}
rowNumber.OrderBy.Clear();
if (orderBy.Count == 0)
{
List <SqlColumn> columns = SqlGatherColumnsProduced.GatherColumns(this.currentSelect.From);
foreach (SqlColumn col in columns)
{
if (col.Expression.SqlType.IsOrderable)
{
orderBy.Add(new SqlOrderExpression(SqlOrderType.Ascending, new SqlColumnRef(col)));
}
}
if (orderBy.Count == 0)
{
// insert simple column
SqlColumn col =
new SqlColumn(
"rowNumberOrder",
sql.Value(typeof(int), this.typeProvider.From(typeof(int)), 1, false, rowNumber.SourceExpression)
);
this.PushDown(col);
orderBy.Add(new SqlOrderExpression(SqlOrderType.Ascending, new SqlColumnRef(col)));
}
}
foreach (SqlOrderExpression sox in orderBy)
{
rowNumber.OrderBy.Add(new SqlOrderExpression(sox.OrderType, (SqlExpression)dup.Duplicate(sox.Expression)));
}
return(rowNumber);
}
internal override SqlSelect VisitSelect(SqlSelect select)
{
bool saveTop = this.topSelect;
bool savePK = this.addPrimaryKeys;
SqlSelect saveSelect = this.currentSelect;
this.currentSelect = select;
if (select.OrderingType == SqlOrderingType.Always)
{
this.addPrimaryKeys = true;
}
this.topSelect = false;
// can't forward ordering information through a group-by
if (select.GroupBy.Count > 0)
{
this.Visit(select.From);
this.orders = null;
}
else
{
this.Visit(select.From);
}
if (select.OrderBy.Count > 0)
{
this.PrependOrderExpressions(select.OrderBy);
}
List <SqlOrderExpression> save = this.orders;
this.orders = null;
this.rowNumberOrders = save; // lest orders be null when we need info
/* do all the lower level stuff */
select.Where = this.VisitExpression(select.Where);
for (int i = 0, n = select.GroupBy.Count; i < n; i++)
{
select.GroupBy[i] = this.VisitExpression(select.GroupBy[i]);
}
select.Having = this.VisitExpression(select.Having);
for (int i = 0, n = select.OrderBy.Count; i < n; i++)
{
select.OrderBy[i].Expression = this.VisitExpression(select.OrderBy[i].Expression);
}
select.Top = this.VisitExpression(select.Top);
select.Selection = this.VisitExpression(select.Selection);
select.Row = (SqlRow)this.Visit(select.Row);
this.topSelect = saveTop;
this.addPrimaryKeys = savePK;
this.orders = save;
// all ordering is blocked for this layer and above
if (select.OrderingType == SqlOrderingType.Blocked)
{
this.orders = null;
}
// rebuild orderby expressions, provided this select doesn't contain a SqlRowNumber
// otherwise, replace the orderby with a reference to that column
select.OrderBy.Clear();
var rowNumberChecker = new SqlRowNumberChecker();
if (rowNumberChecker.HasRowNumber(select) && rowNumberChecker.RowNumberColumn != null)
{
select.Row.Columns.Remove(rowNumberChecker.RowNumberColumn);
this.PushDown(rowNumberChecker.RowNumberColumn);
this.Orders.Add(new SqlOrderExpression(SqlOrderType.Ascending, new SqlColumnRef(rowNumberChecker.RowNumberColumn)));
}
if ((this.topSelect || select.Top != null) && select.OrderingType != SqlOrderingType.Never && this.orders != null)
{
this.orders = new HashSet <SqlOrderExpression>(this.orders).ToList();
SqlDuplicator dup = new SqlDuplicator(true);
foreach (SqlOrderExpression sox in this.orders)
{
select.OrderBy.Add(new SqlOrderExpression(sox.OrderType, (SqlExpression)dup.Duplicate(sox.Expression)));
}
}
this.currentSelect = saveSelect;
return(select);
}