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

您可以用子查询创建一个逗号分隔的列表，并且后面没有最后一个逗号。据说这比之前使用的函数更有效。我想是2005年之后。

SELECT 
    Project.ProjectName,
    (SELECT
        SUBSTRING(
            (SELECT ', ' + Site.SiteName
            FROM Site
            WHERE Site.ProjectKey = Project.ProjectKey
            ORDER BY Project.ProjectName
    FOR XML PATH('')),2,200000)) AS CSV 
FROM Project

您还可以使用带有嵌套查询的FOR XML PATH来选择XML，我发现这很有用。

2011-11-09 19:54:42

其他回答

在Management Studio中，你可以在GO批处理结束标记后面放一个数字，以使批处理重复该次数:

PRINT 'X'
GO 10

将打印'X' 10次。这可以让你在做重复的事情时避免繁琐的复制/粘贴。

2008-09-26 18:13:54

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

2008-09-23 14:18:59

本周我学到的最令人惊讶的事情是在ORDER By子句中使用CASE语句。例如:

declare @orderby varchar(10)

set @orderby = 'NAME'

select * 
    from Users
    ORDER BY 
        CASE @orderby
            WHEN 'NAME' THEN LastName
            WHEN 'EMAIL' THEN EmailAddress
        END

2008-11-26 15:43:39

找出最流行的查询

与系统。Dm_exec_query_stats，您可以通过一个查询计算出许多查询分析的组合。

链接用命令

select * from sys.dm_exec_query_stats 
order by execution_count desc

2008-09-29 17:03:14

SQL Server 2005:

select * from sys.dm_os_performance_counters

select * from sys.dm_exec_requests

2008-09-23 16:05:02

SQL Server的隐藏特性

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