开发中经典sql总结
1、说明：显示文章、提交人和最后回复时间
select a.title,a.username,b.adddate ,(select max(adddate) from table where table.title=a.title) adddate from table a
2、说明：两张关联表，删除主表中已经在副表中没有的信息
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )
3、说明：日程安排提前五分钟提醒
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5
4、说明：一条sql 语句搞定数据库分页
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段
5、说明：选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.)
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b)
6、说明：包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表
(select a from tableA ) except (select a from tableB) except (select a from tableC)
7、说明：随机取出10条数据
select top 10 * from tablename order by newid()
8、说明：删除重复记录
delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)
10、说明：列出数据库里所有的表名
select name from sysobjects where type='U' // U代表用户
11、说明：列出表里的所有的列名
select name from syscolumns where id=object_id('TableName')
12、说明：列示type、vender、pcs字段，以type字段排列，case可以方便地实现多重选择，类似select 中的case。
select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type
13、说明：选择从10到15的记录
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc
14、SQL SERVER中直接循环写入数据
declare @i int
set @i=1
while @i<30
begin
insert into test (userid) values(@i)
set @i=@i+1
end
15 sp_executesql 用法
Declare @SQL nvarchar(max);
Declare @DonatorId int = 2;
Declare @DonatorName varchar(10);
set @SQL = 'SELECT * FROM dbo.Donators WHERE DonatorId = @id';
EXEC sp_executesql
@stmt = @SQL,
@params = N'@id as int',
@id = @DonatorId;
16.select DATENAME(DW,getdate()) as 今天周几
17.查询期刊的档期期期号和下一期期号
SELECT TOP 100 A.[Id]
,A.[Issue]
,(SELECT MIN(ISSUE) FROM [Issue] B WHERE B.Issue>A.Issue ) NextIssue
FROM [Issue] A
18.sqlserver 存储过程事务异常处理
CREATE PROCEDURE YourProcedure
AS
BEGIN
SET NOCOUNT ON;
BEGIN TRY---------------------开始捕捉异常
BEIN TRAN------------------开始事务
UPDATE A SET A.names = B.names FROM 表1 AS A INNER JOIN 表2 AS B ON A.id = B.id
UPDATE A SET A.names = B.names FROM 表1 AS A INNER JOIN 表2 AS B ON A.TEST = B.TEST
COMMIT TRAN -------提交事务
END TRY-----------结束捕捉异常
BEGIN CATCH------------有异常被捕获
SELECT ERROR_NUMBER() AS ErrorNumber,
ERROR_SEVERITY() AS ErrorSeverity,
ERROR_STATE() as ErrorState,
ERROR_PROCEDURE() as ErrorProcedure,
ERROR_LINE() as ErrorLine,
ERROR_MESSAGE() as ErrorMessage;
IF @@TRANCOUNT > 0---------------判断有没有事务
BEGIN
ROLLBACK TRAN----------回滚事务
END
EXEC YourLogErrorProcedure-----------记录存储过程执行时的错误信息，自定义
END CATCH--------结束异常处理
END
19.行列转换
SELECT [Id]
,[StudentName]
,[KeCheng]
,[ChengJi]
FROM [Mytest].[dbo].[ChengJi]
select [StudentName],
max(case(kecheng) when '数学' then chengji end) as '数学',
max(case(kecheng) when '语文' then chengji end) as '语文',
max(case(kecheng) when '英语' then chengji end) as '英语'
from [Mytest].[dbo].[ChengJi] group by [StudentName]
20 计算中null值得处理
SELECT COALESCE('',0) 结果0
SELECT COALESCE(' ',0) 结果0
SELECT COALESCE(null,0) 结果0
SELECT COALESCE(123,0) 结果123
SELECT ISNULL('',0) 结果''
SELECT ISNULL(null,0) 结果0
SELECT ISNULL(123,0) 结果123
由结果结果可以看出COALESCE函数对于空值处理和NULL值都起作用。
21 批量更新数据
update S_USER set account=p.account from S_PERSON p where p.id=S_USER.person_id;
update [ylb_play_type] set PlayOdds= v2.PlayOdds from (select * from [ylb_play_type] where LotteryId=13) v2where [ylb_play_type].LotteryId=14 and v2.PlayName=[ylb_play_type].PlayName
