SQL 查询表中某个字段数据的最大长度

mysql

select
     字段名, length(字段名)
from 
    表名
where
    length(字段名) = (select max(length(字段名)) from 表名 )
    
# 示例：获取user表中的最大长度的name值
select name ,length(name) from user where length(name) = (select max(length(name) from user))

SqlServer

select
    字段名, len(字段名)
from 
    表名
where
    len(字段名) = (select max(len(字段名)) from 表名 )
    
# 示例：获取user表中的最大长度的name值
select name ,len(name) from user where len(name) = (select max(len(name) from user))