public virtual void Visit(SubqueryFactor node)
{
VisitInternal(node.Subquery);
}
/// <returns>
/// type of
/// <see cref="Tup.Cobar4Net.Parser.Ast.Expression.Misc.IQueryExpression" />
/// or
/// <see cref="TableReferences" />
/// </returns>
/// <exception cref="System.SqlSyntaxErrorException" />
private object TrsOrQuery()
{
object @ref;
switch (lexer.Token())
{
case MySqlToken.KwSelect:
{
var select = SelectPrimary();
return BuildUnionSelect(select);
}
case MySqlToken.PuncLeftParen:
{
lexer.NextToken();
@ref = TrsOrQuery();
Match(MySqlToken.PuncRightParen);
if (@ref is IQueryExpression)
{
if (@ref is DmlSelectStatement)
{
IQueryExpression rst = BuildUnionSelect((DmlSelectStatement)@ref);
if (rst != @ref)
{
return rst;
}
}
var alias = As();
if (alias != null)
{
@ref = new SubqueryFactor((IQueryExpression)@ref, alias);
}
else
{
return @ref;
}
}
// ---- build factor complete---------------
@ref = BuildTableReference((TableReference)@ref);
// ---- build ref complete---------------
break;
}
default:
{
@ref = TableReference();
break;
}
}
IList<TableReference> list;
if (lexer.Token() == MySqlToken.PuncComma)
{
list = new List<TableReference>();
list.Add((TableReference)@ref);
for (; lexer.Token() == MySqlToken.PuncComma;)
{
lexer.NextToken();
@ref = TableReference();
list.Add((TableReference)@ref);
}
return new TableReferences(list);
}
list = new List<TableReference>(1);
list.Add((TableReference)@ref);
return new TableReferences(list);
}