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

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

这里有一个简单但有用的例子:

手动编辑表内容时,可以通过输入Control-0在列中插入NULL。

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

空间结果选项卡可以用来创建艺术。

在这里输入链接描述http://michaeljswart.com/wp-content/uploads/2010/02/venus.png

EXCEPT和INTERSECT

在比较两个查询结果时,这两个关键字是一种更优雅的简写和可读的表达查询意图的方式,而不是编写复杂的连接和子查询。作为SQL Server 2005的新版本,它们有力地补充了在TSQL语言中已经存在多年的UNION。

EXCEPT、INTERSECT和UNION是集合论中的基本概念,集合论是所有现代RDBMS使用的关系建模的基础和基础。现在,使用TSQL可以更直观、更容易地生成维恩图类型的结果。