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

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。

我用来将这个存储过程添加到主数据库,

改进:

修剪主机名,这样复制粘贴就可以在VNC上工作。 增加了一个LOCK选项,用于查看当前锁定的进程。

用法:

EXEC sp_who3 'ACTIVE' EXEC sp_who3 'LOCK' EXEC sp_who3 spid_No

就是这样。

CREATE procedure sp_who3
       @loginame sysname = NULL --or 'active' or 'lock'
as

declare  @spidlow   int,
         @spidhigh  int,
         @spid      int,
         @sid       varbinary(85)

select   @spidlow   =     0
        ,@spidhigh  = 32767


if @loginame is not NULL begin
    if upper(@loginame) = 'ACTIVE' begin
        select spid, ecid, status
            , loginame=rtrim(loginame)
            , hostname=rtrim(hostname)
            , blk=convert(char(5),blocked)
            , dbname = case
                            when dbid = 0 then null
                            when dbid <> 0 then db_name(dbid)
                        end
              ,cmd
        from  master.dbo.sysprocesses
        where spid >= @spidlow and spid <= @spidhigh AND
              upper(cmd) <> 'AWAITING COMMAND'
        return (0)
    end
    if upper(@loginame) = 'LOCK' begin
        select spid , ecid, status
            , loginame=rtrim(loginame)
            , hostname=rtrim(hostname)
            , blk=convert(char(5),blocked)
            , dbname = case
                            when dbid = 0 then null
                            when dbid <> 0 then db_name(dbid)
                        end
              ,cmd
        from  master.dbo.sysprocesses
        where spid >= 0 and spid <= 32767 AND
              upper(cmd) <> 'AWAITING COMMAND'
        AND convert(char(5),blocked) > 0
        return (0)
    end

end

if (@loginame is not NULL
   AND  upper(@loginame) <> 'ACTIVE'
   )
begin
    if (@loginame like '[0-9]%')    -- is a spid.
    begin
        select @spid = convert(int, @loginame)
        select spid, ecid, status
            , loginame=rtrim(loginame)
            , hostname=rtrim(hostname)
            , blk=convert(char(5),blocked)
            , dbname = case
                            when dbid = 0 then null
                            when dbid <> 0 then db_name(dbid)
                        end
              ,cmd
        from  master.dbo.sysprocesses
        where spid = @spid
    end
    else
    begin
        select @sid = suser_sid(@loginame)
        if (@sid is null)
        begin
            raiserror(15007,-1,-1,@loginame)
            return (1)
        end
        select spid, ecid, status
            , loginame=rtrim(loginame)
            , hostname=rtrim(hostname)
            , blk=convert(char(5),blocked)
            , dbname = case
                            when dbid = 0 then null
                            when dbid <> 0 then db_name(dbid)
                        end
               ,cmd
        from  master.dbo.sysprocesses
        where sid = @sid
    end
    return (0)
end


/* loginame arg is null */
select spid,
       ecid,
       status
       , loginame=rtrim(loginame)
       , hostname=rtrim(hostname)
       , blk=convert(char(5),blocked)
       , dbname = case
                    when dbid = 0 then null
                    when dbid <> 0 then db_name(dbid)
                end
       ,cmd
from  master.dbo.sysprocesses
where spid >= @spidlow and spid <= @spidhigh


return (0) -- sp_who

好吧,这是我剩下的一些,很遗憾我错过了开始,但继续吧,这里有一些顶级的东西!

查询分析器

Alt+F1对所选文本执行sp_help Alt-D -聚焦到数据库下拉菜单,这样你就可以使用字母光标键选择db。

t - sql

if (object_id("nameofobject") IS NOT NULL) begin <do something> end -最简单的存在性检查 Sp_locks——比sp_who2(这是第一个调用端口)更深入的锁定信息 DBCC inputbuffer(spid) -执行进程的顶部行列表(有点有用,但简单) DBCC outputbuffer(spid) -执行进程输出的顶行列表

通用T-sql技巧

对于大容量的数据,可以自由地使用子查询来处理集合中的数据

例如,获得已婚人士的名单 50岁以上的人可以选择 一群结婚的人 子查询并与一组 同样是50岁以上的人 加入结果-请原谅 的例子

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

批分离器

大多数人都不知道“GO”不是SQL命令。它是客户端工具使用的默认批处理分隔符。你可以在Books Online找到更多信息。

您可以通过在Management Studio中选择“Tools -> Options”,并在“查询执行”部分更改批量分隔符选项来更改批量分隔符选项。

我不知道为什么你想这样做,除了作为一个恶作剧,但这是一个有点有趣的琐事。