public OutputColumnDescriptor ResolveColumnReference(ColumnReferenceExpression node)
{
IQueryModel model = EnsureModel();
if (TryColumnReference(model, node, out QueryColumnBase col))
{
return(ColumnModelToDescriptor(col));
}
throw new NotImplementedException(node.WhatIsThis());
}
private bool TryColumnReference(IQueryModel model, ColumnReferenceExpression node, out QueryColumnBase col)
{
if (node.ColumnType != ColumnType.Regular)
{
throw new NotImplementedException(node.AsText());
}
if (node.MultiPartIdentifier.Count == 2)
{
// source (table/view) name without schema or alias
string sourceNameOrAlias = node.MultiPartIdentifier[0].Dequote();
string columnName = node.MultiPartIdentifier[1].Dequote();
if (model.TryGetQueryOutputColumnByName(this.batchResolver, columnName, out col))
{
return(true);
}
else
{
throw new NotImplementedException(node.WhatIsThis()); // not resolved?
}
}
else if (node.MultiPartIdentifier.Count == 1)
{
// no source only column name => traverse all source and find t
string columnName = node.MultiPartIdentifier[0].Dequote();
if (model.TryGetQueryOutputColumnByName(this.batchResolver, columnName, out col))
{
return(true);
}
else
{
throw new NotImplementedException(node.WhatIsThis()); // not resolved?
}
}
else
{
// 3 or 4
throw new NotImplementedException(node.AsText() + " ## " + statement.WhatIsThis());
}
}
