internal WhereClauseLifter(NodeFactory sql)
{
this.sql = sql;
this.aggregateChecker = new SqlAggregateChecker();
this.rowNumberChecker = new SqlRowNumberChecker();
}
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;
}
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);
}