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

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

其他回答

Use

从information_schema中选择*

列出所有的数据库,基本表,sps,视图等在SQL server。

如果您想删除数据库中的所有过程-

SELECT  IDENTITY ( int, 1, 1 ) id, 
        [name] 
INTO    #tmp 
FROM    sys.procedures 
WHERE   [type]        = 'P' 
    AND is_ms_shipped = 0 

DECLARE @i INT 

SELECT   @i = COUNT( id ) FROM #tmp 
WHILE    @i > 0 
BEGIN 
   DECLARE @name VARCHAR( 100 ) 
   SELECT @name = name FROM #tmp WHERE id = @i 
   EXEC ( 'DROP PROCEDURE ' + @name ) 
   SET @i = @i-1 
END

DROP TABLE #tmp

一个不太为人所知的TSQL技术,以随机顺序返回行:

-- Return rows in a random order
SELECT 
    SomeColumn 
FROM 
    SomeTable
ORDER BY 
    CHECKSUM(NEWID())

SQL Server 2005:

select * from sys.dm_os_performance_counters

select * from sys.dm_exec_requests

通过关键字查找过程

哪些过程包含特定的文本(表名、列名、变量名、TODO等)?

SELECT OBJECT_NAME(ID) FROM SysComments 
WHERE Text LIKE '%SearchString%' 
AND OBJECTPROPERTY(id, 'IsProcedure') = 1