Left join not returning null records

I’am dealing with a pretty basic SQL query, but I cannot understand why the non matching records are not represented with the null values in right table.

I have table A and table B with a composite key and some data in table B that I know that they do not match the key in table A. However, the result set returns only rows with matching keys without non matching (null) records.

SELECT *
FROM TableA a LEFT JOIN
     TableB b
     ON a.Field1 = b.Field1 AND
        a.Field2 = b.Field2    
WHERE b.Field1 IS NULL

I was expecting to see records from table A and those records from table B that do not match to be represented by Nulls.

EDIT************************************************************

Link with sample data and tables:

https://drive.google.com/file/d/1PNlyqO4mwMBOGgQnWVlduiDKaDjSaE8v/view?usp=sharing

Last record in TableB should be seen because value for Field5 differs from value in TableA.

Answer

The problem with your attempt is that you start with the records in TableA then LEFT JOIN against TableB. This forces the engine to only display records from TableA, with additional rows/columns from TableB if they match, but not records from TableB that aren’t on TableA.

Either you want to reverse the join order:

SELECT 
    *
FROM
    TableB b
    LEFT JOIN TableA a ON 
        a.Field1 = b.Field1 AND
        a.Field2 = b.Field2    
WHERE 
    a.Field1 IS NULL -- records from A table shouldn't exist

Or as RIGHT JOIN

SELECT 
    *
FROM TableA a RIGHT JOIN
     TableB b
     ON a.Field1 = b.Field1 AND
        a.Field2 = b.Field2    
WHERE a.Field1 IS NULL  -- records from A table shouldn't exist 

Or a FULL JOIN if you want records from both displayed, even if no match on the other table (no WHERE clause):

SELECT 
    *
FROM TableA a FULL JOIN
     TableB b
     ON a.Field1 = b.Field1 AND
        a.Field2 = b.Field2