SQL Server的隐藏特性

SQL Server有哪些隐藏特性?

例如，没有文档的系统存储过程，做一些非常有用但没有足够文档的事情的技巧?

答案

感谢大家的精彩回答!

存储过程

sp_msforeachtable: Runs a command with '?' replaced with each table name (v6.5 and up) sp_msforeachdb: Runs a command with '?' replaced with each database name (v7 and up) sp_who2: just like sp_who, but with a lot more info for troubleshooting blocks (v7 and up) sp_helptext: If you want the code of a stored procedure, view & UDF sp_tables: return a list of all tables and views of database in scope. sp_stored_procedures: return a list of all stored procedures xp_sscanf: Reads data from the string into the argument locations specified by each format argument. xp_fixeddrives:: Find the fixed drive with largest free space sp_help: If you want to know the table structure, indexes and constraints of a table. Also views and UDFs. Shortcut is Alt+F1

片段

Returning rows in random order All database User Objects by Last Modified Date Return Date Only Find records which date falls somewhere inside the current week. Find records which date occurred last week. Returns the date for the beginning of the current week. Returns the date for the beginning of last week. See the text of a procedure that has been deployed to a server Drop all connections to the database Table Checksum Row Checksum Drop all the procedures in a database Re-map the login Ids correctly after restore Call Stored Procedures from an INSERT statement Find Procedures By Keyword Drop all the procedures in a database Query the transaction log for a database programmatically.

功能

哈希字节（） EncryptByKey 枢轴命令

Misc

Connection String extras TableDiff.exe Triggers for Logon Events (New in Service Pack 2) Boosting performance with persisted-computed-columns (pcc). DEFAULT_SCHEMA setting in sys.database_principles Forced Parameterization Vardecimal Storage Format Figuring out the most popular queries in seconds Scalable Shared Databases Table/Stored Procedure Filter feature in SQL Management Studio Trace flags Number after a GO repeats the batch Security using schemas Encryption using built in encryption functions, views and base tables with triggers

当前回答

这里有一个简单但有用的例子:

手动编辑表内容时，可以通过输入Control-0在列中插入NULL。

2009-12-07 16:01:31

其他回答

使用GETDATE() +或-来计算附近的日期

SELECT GETDATE() - 1 -- yesterday, 1 day ago, 24 hours ago
SELECT GETDATE() - .5 -- 12 hours ago
SELECT GETDATE() - .25 -- 6 hours ago
SELECT GETDATE() - (1 / 24.0) -- 1 hour ago (implicit decimal result after division)

2011-07-14 21:21:39

sp_msforeachtable:运行带有'?替换为每个表名。如。

exec sp_msforeachtable "dbcc dbreindex('?')"

您最多可以为每个表发出3个命令

exec sp_msforeachtable
    @Command1 = 'print ''reindexing table ?''',
    @Command2 = 'dbcc dbreindex(''?'')',
    @Command3 = 'select count (*) [?] from ?'

此外,sp_MSforeachdb

2008-09-23 15:10:24

许多SQL Server开发人员似乎仍然不知道DELETE、INSERT和UPDATE语句中的OUTPUT子句(SQL Server 2005及更新版本)。

知道哪些行被插入、更新或删除是非常有用的，OUTPUT子句可以很容易地做到这一点——它允许访问称为插入和删除的“虚拟”表(就像在触发器中一样):

DELETE FROM (table)
OUTPUT deleted.ID, deleted.Description
WHERE (condition)

如果你在一个有INT IDENTITY主键字段的表中插入值，使用OUTPUT子句，你可以立即获得插入的新ID:

INSERT INTO MyTable(Field1, Field2)
OUTPUT inserted.ID
VALUES (Value1, Value2)

如果你正在更新，知道发生了什么变化是非常有用的——在这种情况下，插入表示更新之后的新值，而删除则指更新之前的旧值:

UPDATE (table)
SET field1 = value1, field2 = value2
OUTPUT inserted.ID, deleted.field1, inserted.field1
WHERE (condition)

如果将返回大量信息，output的输出也可以重定向到临时表或表变量(output INTO @myInfoTable)。

非常有用——却鲜为人知!

Marc

2009-08-07 09:03:38

Stored proc sp_MSdependencies以一种比sp_depends更有用的方式告诉您对象依赖关系。对于某些产品版本，可以方便地暂时禁用子表约束，应用更改然后重新启用子表约束。这是查找依赖于父表的对象的好方法。

这段代码禁用了子表约束:

create table #deps
( oType int,
  oObjName sysname,
  oOwner nvarchar(200),
  oSequence int
)

insert into #deps  
exec sp_MSdependencies @tableName, null, 1315327

exec sp_MSforeachtable @command1 = 'ALTER TABLE ? NOCHECK CONSTRAINT ALL',
@whereand = ' and o.name in (select oObjName from #deps where oType = 8)'

应用更改后，可以运行以下代码重新启用约束:

exec sp_MSforeachtable @command1 = 'ALTER TABLE ? WITH CHECK CHECK CONSTRAINT ALL',
@whereand = ' and o.name in (select oObjName from #deps where oType = 8)'

第三个参数是@flags，它控制列出的依赖项类型。请阅读proc内容，了解如何根据自己的目的更改@flags。该过程使用位掩码来破译您想要返回的内容。

2010-07-20 14:46:19

使用EncryptByKey进行简单加密

2008-09-23 14:34:16

SQL Server的隐藏特性

推荐文章

最新文章

标签