Illegal mix of collations error in MySql

Question

Just got this answer from a previous question and it works a treat!

SELECT username, (SUM(rating)/COUNT(*)) as TheAverage, Count(*) as TheCount  FROM ratings WHERE month='Aug' GROUP BY username HAVING TheCount > 4 ORDER BY TheAverage DESC, TheCount DESC 

But when I stick this extra bit in it gives this error:

Documentation #1267 - Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (latin1_general_ci,IMPLICIT) for operation '='

SELECT username, (SUM(rating)/COUNT(*)) as TheAverage, Count(*) as TheCount FROM  ratings WHERE month='Aug'  **AND username IN (SELECT username FROM users WHERE gender =1)** GROUP BY username HAVING TheCount > 4 ORDER BY TheAverage DESC, TheCount DESC 

The table is:

id, username, rating, month

Answer 1

Here's how to check which columns are the wrong collation:

SELECT table_schema, table_name, column_name, character_set_name, collation_name  FROM information_schema.columns  WHERE collation_name = 'latin1_general_ci'  ORDER BY table_schema, table_name,ordinal_position;  

And here's the query to fix it:

ALTER TABLE tbl_name CONVERT TO CHARACTER SET latin1 COLLATE 'latin1_swedish_ci'; 

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