Mysql is case sensitive

Use BINARY when designing tables

CREATE TABLE user_info ( login_name VARCHAR(20) BINARY );

Automatic case sensitivity when querying

 

Case sensitivity when querying

SELECT `name`,login_name FROM user_info WHERE BINARY login_name='liangningning';（有结果）
SELECT `name`,login_name FROM user_info WHERE BINARY login_name='Liangningning';（无结果）

 user_info table