mysql 查询某个字段SQL语句【mysql语句】
#查询某个字段为空的语句
SELECT * FROM `passport` WHERE `passNickname` IS NULL;
使用方法:SELECT * FROM `表名` WHERE `字段名` IS NULL;
#查询某个字段不为空的语句
SELECT * FROM `passport` WHERE `passNickname` IS NOT NULL;
使用方法:SELECT * FROM `表名` WHERE `字段名` IS NOT NULL;