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

好吧,这是我的观点:

http://dbalink.wordpress.com/2008/10/24/querying-the-object-catalog-and-information-schema-views/

我懒得在这里重新写一遍,所以请查看我的帖子。这对许多人来说可能是微不足道的,但会有一些人会发现它是一颗“隐藏的宝石”。

编辑:

过了一会儿,我决定在这里添加代码,这样您就不必跳转到我的博客来查看代码了。

SELECT  T.NAME AS [TABLE NAME], C.NAME AS [COLUMN NAME], P.NAME AS [DATA TYPE], P.MAX_LENGTH AS[SIZE],   CAST(P.PRECISION AS VARCHAR) +‘/’+ CAST(P.SCALE AS VARCHAR) AS [PRECISION/SCALE]
FROM ADVENTUREWORKS.SYS.OBJECTS AS T
JOIN ADVENTUREWORKS.SYS.COLUMNS AS C
ON T.OBJECT_ID=C.OBJECT_ID
JOIN ADVENTUREWORKS.SYS.TYPES AS P
ON C.SYSTEM_TYPE_ID=P.SYSTEM_TYPE_ID
WHERE T.TYPE_DESC=‘USER_TABLE’;

或者,如果你想拉出所有的用户表,像这样使用CURSOR:

DECLARE @tablename VARCHAR(60)

DECLARE cursor_tablenames CURSOR FOR
SELECT name FROM AdventureWorks.sys.tables

OPEN cursor_tablenames
FETCH NEXT FROM cursor_tablenames INTO @tablename

WHILE @@FETCH_STATUS = 0
BEGIN

SELECT  t.name AS [TABLE Name], c.name AS [COLUMN Name], p.name AS [DATA Type], p.max_length AS[SIZE],   CAST(p.PRECISION AS VARCHAR) +‘/’+ CAST(p.scale AS VARCHAR) AS [PRECISION/Scale]
FROM AdventureWorks.sys.objects AS t
JOIN AdventureWorks.sys.columns AS c
ON t.OBJECT_ID=c.OBJECT_ID
JOIN AdventureWorks.sys.types AS p
ON c.system_type_id=p.system_type_id
WHERE t.name = @tablename
AND t.type_desc=‘USER_TABLE’
ORDER BY t.name ASC

FETCH NEXT FROM cursor_tablenames INTO @tablename
END

CLOSE cursor_tablenames
DEALLOCATE cursor_tablenames

其他参考资料(我的博客):http://dbalink.wordpress.com/2009/01/21/how-to-create-cursor-in-tsql/

其他回答

删除到数据库的所有连接:

Use Master
Go

Declare @dbname sysname

Set @dbname = 'name of database you want to drop connections from'

Declare @spid int
Select @spid = min(spid) from master.dbo.sysprocesses
where dbid = db_id(@dbname)
While @spid Is Not Null
Begin
        Execute ('Kill ' + @spid)
        Select @spid = min(spid) from master.dbo.sysprocesses
        where dbid = db_id(@dbname) and spid > @spid
End

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

以下是一些我认为有用但很多人似乎不知道的功能:

sp_tables

返回可以为的对象列表 在当前环境下查询。 这意味着任何对象都可以出现 在FROM子句中,同义词除外 对象。

Link

sp_stored_procedures

中存储过程的列表 当前环境。

Link

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

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