internal Visitor(bool doLifting, HashSet <SqlAlias> aliasesForLifting, HashSet <SqlExpression> liftedExpressions)
{
this.doLifting = doLifting;
this.aliases = new SqlAliasesReferenced(aliasesForLifting);
this.liftedExpressions = liftedExpressions;
this.canLiftAll = true;
this.aggregateChecker = new SqlAggregateChecker();
}
internal override SqlSelect VisitSelect(SqlSelect select)
{
SelectScope s = expressionSink;
// Don't lift through a TOP.
if (select.Top != null)
{
expressionSink = null;
}
// Don't lift through a GROUP BY (or implicit GROUP BY).
if (select.GroupBy.Count > 0 || this.aggregateChecker.HasAggregates(select))
{
expressionSink = null;
}
// Don't lift through DISTINCT
if (select.IsDistinct)
{
expressionSink = null;
}
if (expressionSink != null)
{
List <SqlColumn> keep = new List <SqlColumn>();
List <SqlColumn> lift = new List <SqlColumn>();
foreach (SqlColumn sc in select.Row.Columns)
{
bool referencesLeftsideAliases = SqlAliasesReferenced.ReferencesAny(sc.Expression, expressionSink.LeftProduction);
bool isLockedExpression = expressionSink.ReferencedExpressions.Contains(sc);
if (referencesLeftsideAliases && !isLockedExpression)
{
lift.Add(sc);
}
else
{
keep.Add(sc);
}
}
select.Row.Columns.Clear();
select.Row.Columns.AddRange(keep);
if (lift.Count > 0)
{
expressionSink.Lifted.Push(lift);
}
}
SqlSelect sel = base.VisitSelect(select);
expressionSink = s;
return(sel);
}
internal Visitor(bool doLifting, HashSet<SqlAlias> aliasesForLifting, HashSet<SqlExpression> liftedExpressions) {
this.doLifting = doLifting;
this.aliases = new SqlAliasesReferenced(aliasesForLifting);
this.referencedColumns = new HashSet<SqlColumn>();
this.liftedExpressions = liftedExpressions;
this.canLiftAll = true;
if (doLifting)
this.lifted = new List<List<SqlColumn>>();
this.aggregateChecker = new SqlAggregateChecker();
}
internal Visitor(SqlAliasesReferenced parent) {
this.parent = parent;
}
internal Visitor(SqlAliasesReferenced parent)
{
this.parent = parent;
}