Toad-for-SQL-Server-Freeware
1.查询哪些数据库对象使用了某个表
SELECT b.[name], a.[definition] FROM sys.all_sql_modules a, sysobjects b WHERE a.[object_id] = id AND definition LIKE '%表名%'
2.查询表的某一列，将结果变成用逗号分隔的字符串
select col+',' from mytable for xml path('')
排序：
create table pd(col1 varchar(5),col2 int) insert into pd select 'A',3 union all select 'A',2 union all select 'A',1 union all select 'B',2 union all select 'B',1 select a.col1, stuff((select ','+rtrim(b.col2) from pd b where b.col1=a.col1 order by b.col2 for xml path('')),1,1,'') 'col2' from pd a group by a.col1
3.查询有哪些表的表名包含“storeroom”
select * from sysobjects obj where LOWER(obj.name) LIKE N'%storeroom%' and xtype='U'
4.分组条件求和
DECLARE @t1 TABLE ( c1 NUMERIC (12), c2 VARCHAR (30) ) INSERT INTO @t1 (c1, c2) VALUES (1, 'a'); INSERT INTO @t1 (c1, c2) VALUES (2, 'a'); INSERT INTO @t1 (c1, c2) VALUES (3, 'b'); INSERT INTO @t1 (c1, c2) VALUES (4, 'b'); SELECT CASE WHEN max (c1) > 3 THEN sum (c1) ELSE 0 END AS c FROM @t1 GROUP BY c2; /* 结果: c 0 7 */
5.求某一天所在星期的周日
http://www.cnblogs.com/wsdj-ITtech/archive/2011/10/06/2199736.html
USE [MSSQL] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE FUNCTION [dbo].[My_OneDay_GetWeekFirstAndEndDay](@tmpDate DATETIME) RETURNS @tmpTable TABLE(FirstDay DATETIME , EndDay DATETIME) AS BEGIN INSERT INTO @tmpTable SELECT a.FirstDay,b.EndDay FROM ( SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 0) AS FirstDAy ) a LEFT JOIN ( SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 6) AS EndDay ) b ON a.ID = b.ID RETURN END
SELECT * from My_OneDay_GetWeekFirstAndEndDay('2010-09-01')
6.求时间段内周日的数量
http://www.cnblogs.com/wsdj-ITtech/archive/2011/10/06/2199736.html
CREATE FUNCTION [dbo].[MY_Range_GetWeekFirstAndEndDays](@tmpDateSTART DATETIME,@tmpDateEND DATETIME) RETURNS @tmpTable TABLE(WeekOrder INT,FirstDay DATETIME , EndDay DATETIME) AS BEGIN DECLARE @tmpDate DATETIME DECLARE @index INT SET @tmpDate=@tmpDateSTART SET @index=1 WHILE @tmpDate <=@tmpDateEND BEGIN INSERT INTO @tmpTable SELECT @index,a.FirstDay,b.EndDay FROM ( SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 0) AS FirstDAy) a LEFT JOIN ( SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 6) AS EndDay) b ON a.ID = b.ID SET @tmpDate=DATEADD(DAY,7,@tmpDate) SET @index=@index+1 END RETURN END
SELECT * from My_Range_GetWeekFirstAndEndDays('2011-09-01','2011-10-06')
不使用临时表：
DECLARE @tmpDateSTART DATETIME DECLARE @tmpDateEND DATETIME SET @tmpDateSTART = '2015-1-1' SET @tmpDateEND = '2015-1-21' DECLARE @tmpDate DATETIME DECLARE @days INT SET @tmpDate = @tmpDateSTART SET @days = 0 WHILE @tmpDate <= @tmpDateEND BEGIN DECLARE @theDate DATETIME; SET @theDate = DATEADD (wk, DATEDIFF (wk, 0, @tmpDate), 6); IF @theDate > @tmpDateSTART AND @theDate < @tmpDateEND SET @days = @days + 1 SET @tmpDate = DATEADD (DAY, 7, @tmpDate) END SELECT @days
7.查看正在执行的
SELECT [Spid] = session_Id, ecid, [Database] = DB_NAME (sp.dbid), [User] = nt_username, [Status] = er.status, [Wait] = wait_type, [Individual Query] = SUBSTRING ( qt.text, er.statement_start_offset / 2, ( CASE WHEN er.statement_end_offset = -1 THEN LEN (CONVERT (NVARCHAR (MAX), qt.text)) * 2 ELSE er.statement_end_offset END - er.statement_start_offset) / 2), [Parent Query] = qt.text, Program = program_name, Hostname, nt_domain, start_time, datediff (second, start_time, getdate ()) FROM sys.dm_exec_requests er INNER JOIN sys.sysprocesses sp ON er.session_id = sp.spid CROSS APPLY sys.dm_exec_sql_text (er.sql_handle) AS qt WHERE session_Id > 50 -- Ignore system spids. AND session_Id NOT IN (@@SPID) -- Ignore this current statement. ORDER BY datediff (second, start_time, getdate ()) DESC
8.生成GUID
C#中用Guid.NewGuid().ToString()
Sql中用NEWID()
以上方法生成的是36位的GUID，如果需要转换成32位，则需要替换掉其中的'-'字符。
Sql中的方法：replace(newid(), '-', '')
9.时间段统计
--将时间转换为小时 --例如8：22分转换为9 --查询语句如下 SELECT cast ( datepart ( hh, dateadd ( mi, ( datediff (mi, CONVERT (VARCHAR (10), getdate (), 112), getdate ()) / 60 + 1) * 60, CONVERT (VARCHAR (10), getdate (), 112))) AS INT)
http://bbs.csdn.net/topics/190127317 --环境 declare @t table ( 时间 datetime, 金额 int ) insert @t select '2007-1-1 10:00:23', 8 union all select '2007-1-1 10:01:24', 4 union all select '2007-1-1 10:05:00', 2 union all select '2007-1-1 10:06:12', 3 union all select '2007-1-1 10:08:00', 1 union all select '2007-1-1 10:12:11', 5 select dateadd(mi,(datediff(mi,convert(varchar(10),时间,112),时间)/5+1)*5,convert(varchar(10),时间,112)) as 时间段, count(*) as 行数,sum(金额) as 总金额 from @t group by dateadd(mi,(datediff(mi,convert(varchar(10),时间,112),时间)/5+1)*5,convert(varchar(10),时间,112)) --结果 时间段 行数 总金额 ------------------------------------------------------ ----------- ----------- 2007-01-01 10:05:00.000 2 12 2007-01-01 10:10:00.000 3 6 2007-01-01 10:15:00.000 1 5 （所影响的行数为 3 行）
10.存储过程，有时执行很慢
现在的解决办法是，将存储过程中加个空格，alter一下。
exec 存储过程 with recompile
http://bbs.csdn.net/topics/340185343
http://my.oschina.net/HenuToater/blog/177175
http://havebb.com/b/post/produce-suddenly-slow.aspx
http://www.cnblogs.com/luckylei66/archive/2012/07/30/2615000.html
SQL优化之存储过程强制编译 ASP.NET调用SQL后台存储过程时，有时突然就变得很慢，在后台直接执行存储过程没问题，但在前台调用存储过程时就是很慢，而且在前台调用成功后，再次调用还是一样的慢，但更新一下存储过程再调用就很快了。但这始终不能彻底解决问题，过段时间又会出来同样的问题。环境（NET4.0+SQL2008R2) 解决办法： 方法一：在可能比较耗时的语句后面加上option(recompile) 方法二：强制编译存储过程 SQL Server 提供三种重新编译存储过程的方法： (1)、sp_recompile 系统存储过程强制在下次运行存储过程时进行重新编译。 示例：exec sp_recompile 存储过程名 (2)、创建存储过程时在其定义中指定 WITH RECOMPILE 选项，表明 SQL Server 将不对该存储过程计划进行高速缓存；该存储过程将在每次执行时都重新编译。 示例：Create Proc 存储过程名 WITH RECOMPILE AS 参数 (3)、在执行存储过程时指定 WITH RECOMPILE 选项，可强制对存储过程进行重新编译。仅当所提供的参数不典型，或者自创建该存储过程后数据发生显著更改时才应使用此选项。 示例：存储过程名 WITH RECOMPILE