Mysql 表字段null值,更新为0值

示例

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