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

表校验和

Select CheckSum_Agg(Binary_CheckSum(*)) From Table With (NOLOCK)

行校验和

Select CheckSum_Agg(Binary_CheckSum(*)) From Table With (NOLOCK) Where Column = Value

其他回答

好吧,这是我剩下的一些,很遗憾我错过了开始,但继续吧,这里有一些顶级的东西!

查询分析器

Alt+F1对所选文本执行sp_help Alt-D -聚焦到数据库下拉菜单,这样你就可以使用字母光标键选择db。

t - sql

if (object_id("nameofobject") IS NOT NULL) begin <do something> end -最简单的存在性检查 Sp_locks——比sp_who2(这是第一个调用端口)更深入的锁定信息 DBCC inputbuffer(spid) -执行进程的顶部行列表(有点有用,但简单) DBCC outputbuffer(spid) -执行进程输出的顶行列表

通用T-sql技巧

对于大容量的数据,可以自由地使用子查询来处理集合中的数据

例如,获得已婚人士的名单 50岁以上的人可以选择 一群结婚的人 子查询并与一组 同样是50岁以上的人 加入结果-请原谅 的例子

仅限返回日期

Select Cast(Floor(Cast(Getdate() As Float))As Datetime)

or

Select DateAdd(Day, 0, DateDiff(Day, 0, Getdate()))

登录事件的触发器

Logon triggers can help complement auditing and compliance. For example, logon events can be used for enforcing rules on connections (for example limiting connection through a specific username or limiting connections through a username to a specific time periods) or simply for tracking and recording general connection activity. Just like in any trigger, ROLLBACK cancels the operation that is in execution. In the case of logon event that means canceling the connection establishment. Logon events do not fire when the server is started in the minimal configuration mode or when a connection is established through dedicated admin connection (DAC).

Link

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

Vardecimal存储格式

SQL Server 2005为数字和十进制数据类型添加了一种新的存储格式,称为vardecimal。Vardecimal是十进制类型的一种变长表示,可以在行的每个实例中保存未使用的字节。如果十进制定义很大(如decimal(38,6)),但存储的值很小(如0.0),或者有大量重复值,或者数据填充稀疏,则可以节省最多的时间。

Link