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

仅限返回日期

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

or

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

其他回答

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

我最喜欢master..xp_cmdshell。它允许您从服务器上的命令提示符运行命令并查看输出。如果你不能登录到服务器,但你需要获取信息或以某种方式控制它,它是非常有用的。

例如,列出运行SQL server的服务器C:驱动器上的文件夹。

主. .Xp_cmdshell ` dir c:\ `

您还可以启动和停止服务。

主. .xp_cmdshell的sc查询“My . 服务”的 主. .xp_cmdshell 'sc stop“My . 服务”的 主. .xp_cmdshell 'sc start“My . 服务”的

它很强大,但也有安全隐患。许多人禁用它,因为它很容易被用来在服务器上做坏事。但是,如果你能接触到它,它会非常有用。

use db
go 

select o.name 
, (SELECT [definition] AS [text()] 
     FROM sys.all_sql_modules 
     WHERE sys.all_sql_modules.object_id=a.object_id 
     FOR XML PATH(''), TYPE
  )  AS Statement_Text
 , a.object_id
 , o.modify_date 

 FROM sys.all_sql_modules a 
 LEFT JOIN  sys.objects o ON a.object_id=o.object_id 
 ORDER BY  4 desc

--select * from sys.objects

SQL Server 2005:

select * from sys.dm_os_performance_counters

select * from sys.dm_exec_requests

sp_msforeachtable:运行带有'?替换为每个表名。 如。

exec sp_msforeachtable "dbcc dbreindex('?')"

您最多可以为每个表发出3个命令

exec sp_msforeachtable
    @Command1 = 'print ''reindexing table ?''',
    @Command2 = 'dbcc dbreindex(''?'')',
    @Command3 = 'select count (*) [?] from ?'

此外,sp_MSforeachdb