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         


        

Answer 1

[MySQL]

In these (very rare) cases:

• two tables that really need different collation types

• values not coming from a table, but from an explicit enumeration, for instance:

  SELECT 1 AS numbers UNION ALL SELECT 2 UNION ALL SELECT 3

you can compare the values between the different tables by using CAST or CONVERT:

CAST('my text' AS CHAR CHARACTER SET utf8)

CONVERT('my text' USING utf8)

See CONVERT and CAST documentation on MySQL website.

Answer 2

You need to change each column Collation from latin1_general_ci to latin1_swedish_ci

Answer 3

I have the same problem with collection warning for a field that is set from 0 to 1. All columns collections was the same. We try to change collections again but nothing fix this issue.

At the end we update the field to NULL and after that we update to 1 and this overcomes the collection problem.

Answer 4

Use ascii_bin where ever possible, it will match up with almost any collation. A username seldom accepts special characters anyway.

Answer 5

Check the collation type of each table, and make sure that they have the same collation.

After that check also the collation type of each table field that you have use in operation.

I had encountered the same error, and that tricks works on me.

Answer 6

I also got same error, but in my case main problem was in where condition the parameter that i'm checking was having some unknown hidden character (+%A0)

When A0 convert I got 160 but 160 was out of the range of the character that db knows, that's why database cannot recognize it as character other thing is my table column is varchar

• the solution that I did was I checked there is some characters like that and remove those before run the sql command

• ex:- preg_replace('/\D/', '', $myParameter);