public override QsiTableNode VisitFromItem(FromItem item)
{
if (item.getAlias()?.getAliasColumns()?.size() > 0)
{
throw new QsiException(QsiError.Syntax);
}
return(base.VisitFromItem(item));
}
private Column findColumnInAliasedTable(Column column, FromItem fromItem, String aliasPart, String columnPart)
{
if (column != null)
{
// ensure that if the column has already been found, return it
return(column);
}
Table table = fromItem.getTable();
if (table != null)
{
String alias = fromItem.getAlias();
if (alias != null && alias.Equals(aliasPart))
{
column = table.getColumnByName(columnPart);
}
}
else
{
FromItem leftSide = fromItem.getLeftSide();
column = findColumnInAliasedTable(column, leftSide, aliasPart, columnPart);
FromItem rightSide = fromItem.getRightSide();
column = findColumnInAliasedTable(column, rightSide, aliasPart, columnPart);
if (column != null)
{
Query subQuery = fromItem.getSubQuery();
if (subQuery != null)
{
List <FromItem> items = subQuery.getFromClause().getItems();
foreach (FromItem subQueryFromItem in items)
{
column = findColumnInAliasedTable(column, subQueryFromItem, aliasPart, columnPart);
}
}
}
}
return(column);
}