QL0020 Column Mapping Warning
The projected columns do not map cleanly to the expected model shape.
When It Appears
- Mapping validation compares selected columns with model expectations
- Naming mismatches and projection drift commonly surface as warnings
What To Check
- Selected column aliases
- Model property names
- Current mapping assumptions and limitations
Example
var query = new SqlQuery("SELECT customer_id AS Id, customer_name AS FullName FROM dbo.customers");
Assert.True(query.IsValid || query.Warnings.Count >= 0);