public override void Bind(BindContext context)
{
Debug.Assert(IsLeaf());
Debug.Assert(tabRef_ is null);
Debug.Assert(tabName_ == tableName_());
// if table name is not given, search through all tablerefs
isParameter_ = false;
tabRef_ = context.GetTableRef(tabName_, colName_);
// we can't find the column in current context, so it could an outer reference
if (tabRef_ is null)
{
// can't find in my current context, try my ancestors levels up: order is important
// as we are matching naming with the order closest first
// ... from A ... ( from A where exists (... from B where b1 > a.a1))
// so a.a1 matches the inner side A.
//
BindContext parent = context;
while ((parent = parent.parent_) != null)
{
tabRef_ = parent.GetTableRef(tabName_, colName_);
if (tabRef_ != null)
{
// we are actually switch the context to parent, whichTab_ is not right ...
isParameter_ = true;
tabRef_.colRefedBySubq_.Add(this);
// mark myself a correlated query and remember whom I am correlated to
var mystmt = context.stmt_ as SelectStmt;
mystmt.isCorrelated_ = true;
mystmt.correlatedWhich_.Add(parent.stmt_ as SelectStmt);
context = parent;
break;
}
}
if (tabRef_ is null)
{
throw new SemanticAnalyzeException($"can't bind column '{colName_}' to table");
}
}
// we have identified the tableRef this belongs to, make sure outputName not conflicting
// Eg. select c1 as c2, ... from c
if (!outputName_.Equals(colName_) &&
tabRef_.LocateColumn(outputName_) != null)
{
throw new SemanticAnalyzeException($"conflicting output name {outputName_} is not allowed");
}
Debug.Assert(tabRef_ != null);
if (!isParameter_)
{
Debug.Assert(tableRefs_.Count == 0);
tableRefs_.Add(tabRef_);
}
// FIXME: we shall not decide ordinal_ so early but if not, hard to handle outerref
ordinal_ = context.ColumnOrdinal(tabRef_.alias_, colName_, out ColumnType type);
type_ = type;
markBounded();
}
