select * from table where cast(字段 as date) is null
BIT_LENGTH(str)返回字符串的比特長度CONCAT(s1,s2...,sn)將s1,s2...,sn連接成字符串CONCAT_WS(sep,s1,s2...,sn)將s1,s2...,sn連接成字符串,並用sep字符間隔INS