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

我知道它并不是完全隐藏的，但是没有太多人知道PIVOT命令。我能够改变一个使用游标的存储过程，并花费2分钟来运行一段6秒的代码，而这段代码的行数是原来的十分之一!

2008-10-08 23:36:51

其他回答

在SQL Server 2005/2008中显示SELECT查询结果中的行号:

SELECT ( ROW_NUMBER() OVER (ORDER BY OrderId) ) AS RowNumber,
        GrandTotal, CustomerId, PurchaseDate
FROM Orders

ORDER BY是一个强制性条款。OVER()子句告诉SQL引擎对指定列(在本例中为OrderId)上的数据进行排序，并根据排序结果分配数字。

2009-02-10 15:22:30

SQL Server 2005:

select * from sys.dm_os_performance_counters

select * from sys.dm_exec_requests

2008-09-23 16:05:02

强制参数化

参数化允许SQL Server利用查询计划重用，并避免后续执行类似查询时的编译和优化开销。然而，由于这样或那样的原因，仍然有许多应用程序存在特殊的查询编译开销。对于查询编译次数较多、降低CPU利用率和响应时间对工作负载至关重要的情况，强制参数化可以提供帮助。

Link

2008-09-29 17:02:20

跟踪旗帜!“1204”在SQL Server 2000上的死锁调试中是无价的(2005有更好的工具)。

2008-09-24 13:11:34

用于解析存储过程参数:xp_sscanf

将数据从字符串读入每个格式参数指定的参数位置。下面的示例使用xp_sscanf 从源中提取两个值属性中的位置源字符串的格式。

DECLARE @filename varchar (20), @message varchar (20)
EXEC xp_sscanf 'sync -b -fproducts10.tmp -rrandom', 'sync -b -f%s -r%s', 
  @filename OUTPUT, @message OUTPUT
SELECT @filename, @message

这是结果集。

-------------------- -------------------- 
products10.tmp        random

2008-09-23 14:47:43

SQL Server的隐藏特性

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