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

SQL Server 2005:

select * from sys.dm_os_performance_counters

select * from sys.dm_exec_requests

其他回答

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。

下面是我写的一个查询,按最后修改日期列出所有DB用户对象:

select name, modify_date, 
case when type_desc = 'USER_TABLE' then 'Table'
when type_desc = 'SQL_STORED_PROCEDURE' then 'Stored Procedure'
when type_desc in ('SQL_INLINE_TABLE_VALUED_FUNCTION', 'SQL_SCALAR_FUNCTION', 'SQL_TABLE_VALUED_FUNCTION') then 'Function'
end as type_desc
from sys.objects
where type in ('U', 'P', 'FN', 'IF', 'TF')
and is_ms_shipped = 0
order by 2 desc

在sys.database_principles中设置DEFAULT_SCHEMA

SQL Server在名称解析方面提供了极大的灵活性。然而,名称解析是有代价的,并且在不完全限定对象引用的临时工作负载中可能会显着昂贵。SQL Server 2005允许为每个数据库原则(也称为“user”)设置新的DEFEAULT_SCHEMA,这可以在不更改TSQL代码的情况下消除这种开销。

Link

HashBytes()返回其输入的MD2、MD4、MD5、SHA或SHA1哈希值。

@Gatekiller -一个更简单的方法来获得日期肯定是

CAST(CONVERT(varchar,getdate(),103) as datetime)

如果在本地不使用DD/MM/YYYY,则需要使用与103不同的值。SQL Books Online中的查找转换函数用于区域代码。