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

在SQL Server 2005/2008中显示SELECT查询结果中的行号:

SELECT ( ROW_NUMBER() OVER (ORDER BY OrderId) ) AS RowNumber,
        GrandTotal, CustomerId, PurchaseDate
FROM Orders

ORDER BY是一个强制性条款。OVER()子句告诉SQL引擎对指定列(在本例中为OrderId)上的数据进行排序,并根据排序结果分配数字。

其他回答

表/存储过程过滤器是一个半隐藏的特性,非常有用…

在“SQL Server Management Studio对象资源管理器”中,右键单击“表或存储过程”文件夹,选择“筛选器”菜单,然后选择“筛选器设置”,并在“名称包含”行中输入部分名称。

同样地,使用Remove Filter再次查看所有表/存储过程。

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。

Persisted-computed-columns

计算列可以帮助您将运行时计算成本转移到数据修改阶段。计算列与行其余部分一起存储,当计算列上的表达式与查询匹配时,将透明地使用它。您还可以在PCC上构建索引,以加快表达式的过滤和范围扫描。

Link

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。

在恢复数据库用于测试或其他用途时非常有用。正确地重新映射登录ID:

EXEC sp_change_users_login 'Auto_Fix', 'Mary', NULL, 'B3r12-36'