Mysql Null值处理

Mysql 表字段null值，更新为0值

UPDATE axin_member
SET create_time = ( CASE WHEN IFNULL( create_time, '' ) = '' THEN 0 ELSE create_time END )
WHERE
create_time IS NULL

Mysql 表字段null值，更新为空字符串（即：’’，”EMPTY STRING”）值

UPDATE axin_member
SET nickname = ( CASE WHEN IFNULL( nickname, '' ) = '' THEN '' ELSE nickname END )
WHERE
nickname IS NULL