MySQL Locate Duplicates between two table with similar column

Question

Using this question's answer. I'm trying to find duplicate records between two tables by the column names matrix_unique_id and Matrix_Unique_ID in each table and then display the full address. The Full address columns are formatted differently from each other in each table so I cannot use that as a comparison. I'm getting an "unknown column fort_property_res.matrix_unique_id" error but everything looks okay?

So two questions:

1. Will this query find duplicates correctly?

2. Why the unknown column error?

SQL query:

SELECT matrix_unique_id, full_address 
FROM fort_property_res
INNER JOIN (
    SELECT Matrix_Unique_ID, FullAddress 
    FROM sunshinemls_property_res
    GROUP BY FullAddress 
    HAVING count(fort_property_res.matrix_unique_id) > 1
) dup ON fort_property_res.matrix_unique = sunshinemls_property_res.Matrix_Unique_ID

Answer 1

The solution you're trying to copy is a totally different case. You have two tables and (it looks like) a convenient matrix_unique_id to join on, so this is much easier:

SELECT fort.matrix_unique_id, fort.full_address AS fortAddress, sun.FullAddress AS sunAddress
FROM fort_property_res fort, sunshinemls_property_res sun
WHERE fort.matrix_unique_id = sun.Matrix_Unique_ID