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

有时没有合适的列来排序，或者您只是想要表上的默认排序顺序，并且希望枚举每一行。为了做到这一点，你可以把“(select 1)”放在“order by”子句中，你就会得到你想要的东西。整洁的,是吗?

select row_number() over (order by (select 1)), * from dbo.Table as t

2010-09-05 15:37:31

其他回答

我不确定这是否是一个隐藏的功能，但我偶然发现了这个功能，并发现它在很多情况下都很有用。您可以在单个选择语句中连接一组字段，而不是使用游标并遍历选择语句。

例子:

DECLARE @nvcConcatonated nvarchar(max)
SET @nvcConcatonated = ''

SELECT @nvcConcatonated = @nvcConcatonated + C.CompanyName + ', '
FROM tblCompany C
WHERE C.CompanyID IN (1,2,3)

SELECT @nvcConcatonated

结果:

Acme, Microsoft, Apple,

2009-05-21 18:10:32

CTRL-E在查询分析器中执行当前选择的文本。

2009-07-16 21:09:07

SQLCMD

如果您有脚本需要反复运行，但必须更改轻微的细节，那么在sqlcmd模式下运行ssms非常棒。sqlcmd命令行也非常漂亮。

我最喜欢的特点是:

你需要设置变量。适当的变量，不需要跳过sp_exec圈您可以一个接一个地运行多个脚本这些脚本可以引用“外部”脚本中的变量

Red Gate的Simpletalk没有再滔滔滔滔地说什么，而是对sqlcmd - sqlcmd工作台做了一个很棒的总结。Donabel Santos也有一些很棒的SQLCMD示例。

2009-06-23 09:53:23

如果你想要存储过程的代码，你可以:

sp_helptext 'ProcedureName'

(不确定是否是隐藏功能，但我一直在使用它)

2008-09-23 16:56:14

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

SQL Server的隐藏特性

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