Trouble with "Illegal Mix of Collations" Error in MySql
Encountering the "Illegal mix of collations" error while executing a query can be frustrating. To resolve this issue, follow these steps:
Check Collations
First, identify the columns with incompatible collations. Run the following query:
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;
Fix Collation Inconsistencies
Once you have identified the offending columns, adjust their collations to match the required collation using the following query:
ALTER TABLE tbl_name CONVERT TO CHARACTER SET latin1 COLLATE 'latin1_swedish_ci';
Replace "tbl_name" with the name of the table with the collation inconsistencies.
Example
Applying these steps to the example query provided will resolve the problem:
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
Cautions
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