SQL修改数据表字段长度

alter table m_Assysn_t nocheck CONSTRAINT all
Alter Table m_Assysn_t ALTER column ppid VARCHAR(150)
alter table m_Assysn_t check constraint all
Alter Table dbo.[T_STAT_ADMIN] ALTER column INIText VARCHAR(8000)
 

SUM操作的字符串到数值型的转换:

select sum(cast(变量 as bigint)) as 变量 from 表
例:select sum(cast(studentid as bigint)) as he from student

posted @ 2018-02-18 05:03  herizai  阅读(4879)  评论(0编辑  收藏  举报