- 关于怎么打开xp_cmdshell的方法：
exec sp_configure ‘show advanced option‘,1
reconfigure
go
exec sp_configure ‘xp_cmdshell‘,1
reconfigure
go - 关于截取表字段名称：
select NewName=left(trim(name),1) from student - SQL临时表的用法：
select * into #A from student 将student内容插入到临时表#A - SQL添加表外键关联：
alter table borrow add constraint FK_student foreign key(stuID) references student(stuID) - SQL多表查询：
select stuent.stuName,stuent.stuID,book.title,book.BID,borrow.T_time from student,book,borrow where student.stuID=borrow.stuID,book.BID=borrow.BID,borrow.T_time between ‘2007-12-15‘ and ‘2008-1-8‘ - SQL根据表数据的个数添加对应的序号：
update stu
set sCount =
(select Temp.value from (select sCode, value = 20 * ROW_NUMBER() over (order by sCode ) from stu) as Temp where Temp.scode = stu.sCode ) - SQL创建聚集索引和非聚集索引：
CREATE CLUSTERED INDEX IX_Id ON Person(Id)CREATE NONCLUSTERED INDEX IX_Name ON Person(Name) --创建非聚集索引
时间： 2024-08-07 05:20:06