数据库操作

1. 查询表有多少行

SELECT count([id])    FROM [AchieveDB].[dbo].[StudentT]

 

2. 将年级为2013的学生密码置为NULL

UPDATE [AchieveDB].[dbo].[StudentT]
   SET [Passwd] = NULL
 WHERE [Grade]= '2013'

 

3. 将年纪为2013的学生密码职位出生日期

UPDATE [AchieveDB].[dbo].[StudentT]
   SET [Passwd] = [Birthday]
 WHERE [Grade]= '2013'

 

4. 把表sheet1$插入到表StudentT后面

insert into [AchieveDB].[dbo].[StudentT]
     SELECT * FROM [AchieveDB].[dbo].[Sheet1$]