без учета регистра

STRCMP(expr1,expr2)

STRCMP() returns 0 if the strings are the same, -1 if the first argument is smaller than the second according to the current sort order, and 1 otherwise.

mysql> SELECT STRCMP('text', 'text2');
-> -1
mysql> SELECT STRCMP('text2', 'text');
-> 1
mysql> SELECT STRCMP('text', 'text');
-> 0

STRCMP() uses the current character set when performing comparisons. This makes the default comparison behavior case insensitive unless one or both of the operands are binary strings.

 

SELECT UPPER('VASYA') = UPPER('vasya');
Вернет 1.

Хотя по идее MySQL сравнивает их и так без учета регистра.

SELECT 'VASYA' = 'vasya';
Вернет 1.

 

Коллэйшн на поле нужный выставить.