Returns the collation of the string argument.
SELECT COLLATION('abc');
'utf8mb4_0900_ai_ci'
SELECT COLLATION(_utf8mb4'abc');
'utf8mb4_0900_ai_ci'
SELECT COLLATION(_latin1'abc');
'latin1_swedish_ci'
SELECT COLLATION('abc');
'utf8mb4_0900_ai_ci'
SELECT COLLATION(_utf8mb4'abc');
'utf8mb4_0900_ai_ci'
SELECT COLLATION(_latin1'abc');
'latin1_swedish_ci'