转载 详解SQL Server的两个存储过程sp_MSforeachtablesp_MSforeachdb

转载 详解SQL Server的两个存储过程sp_MSforeachtablesp_MSforeachdb 

1.简介:
 作为DBA会经常需要检查所有的数据库或用户表,比如:检查所有数据库的容量;看看指定数据库所有用户表的容量,所有表的记录数...,我们一般处理这样的问题都是用游标分别处理处理,比如:在数据库检索效率非常慢时,我们想检查数据库所有的用户表,我们就必须通过写游标来达到要求；如果我们用sp_MSforeachtable就可以非常方便的达到相同的目的:EXEC sp_MSforeachtable @command1="print '?' DBCC CHECKTABLE ('?')"
 系统存储过程sp_MSforeachtable和sp_MSforeachdb,是微软提供的两个不公开的存储过程,从mssql6.5开始。存放在SQL Server的MASTER数据库中。可以用来对某个数据库的所有表或某个SQL服务器上的所有数据库进行管理，后面将对此进行详细介绍。
2.参数说明:
 @command1 nvarchar（2000）, --第一条运行的SQL指令
 @replacechar nchar（1） = N'?', --指定的占位符号 
 @command2 nvarchar（2000）= null, --第二条运行的SQL指令
 @command3 nvarchar（2000）= null, --第三条运行的SQL指令
 @whereand nvarchar（2000）= null, --可选条件来选择表
 @precommand nvarchar（2000）= null, --执行指令前的操作(类似控件的触发前的操作)
 @postcommand nvarchar（2000）= null --执行指令后的操作(类似控件的触发后的操作)
 以后为sp_MSforeachtable的参数，sp_MSforeachdb不包括参数@whereand
3.使用举例:
 --统计数据库里每个表的详细情况：
 exec sp_MSforeachtable @command1="sp_spaceused '?'"
 --获得每个表的记录数和容量:
 EXEC sp_MSforeachtable @command1="print '?'",
 @command2="sp_spaceused '?'",
 @command3= "SELECT count(*) FROM ? "
 --获得所有的数据库的存储空间:
 EXEC sp_MSforeachdb @command1="print '?'",
 @command2="sp_spaceused "
 --检查所有的数据库
 EXEC sp_MSforeachdb @command1="print '?'",
 @command2="DBCC CHECKDB (?) "
 --更新PUBS数据库中已t开头的所有表的统计:
 EXEC sp_MSforeachtable @whereand="and name like 't%'",
 @replacechar='*',
 @precommand="print 'Updating Statistics.....' print ''",
 @command1="print '*' update statistics * ",
 @postcommand= "print''print 'Complete Update Statistics!'"
 --删除当前数据库所有表中的数据
 sp_MSforeachtable @command1='Delete from ?'
 sp_MSforeachtable @command1 = "TRUNCATE TABLE ?" 
4.参数@whereand的用法：
 @whereand参数在存储过程中起到指令条件限制的作用，具体的写法如下：
 @whereend,可以这么写 @whereand=' AND o.name in (''Table1'',''Table2'',.......)'
 例如：我想更新Table1/Table2/Table3中NOTE列为NULL的值
 sp_MSforeachtable @command1='Update ? Set NOTE='''' Where NOTE is NULL',@whereand=' AND o.name in (''Table1'',''Table2'',''Table3'')'
5."?"在存储过程的特殊用法,造就了这两个功能强大的存储过程.
 这里"?"的作用,相当于DOS命令中、以及我们在WINDOWS下搜索文件时的通配符的作用。 
6.小结
 有了上面的分析,我们可以建立自己的sp_MSforeachObject:（转贴）
USE MASTER
GO
CREATE proc sp_MSforeachObject
@objectType int=1,
@command1 nvarchar(2000), 
@replacechar nchar(1) = N'?', 
@command2 nvarchar(2000) = null,
@command3 nvarchar(2000) = null, 
@whereand nvarchar(2000) = null,
@precommand nvarchar(2000) = null, 
@postcommand nvarchar(2000) = null
as
/* This proc returns one or more rows for each table (optionally, matching @where), with each table defaulting to its 
own result set */
/* @precommand and @postcommand may be used to force a single result set via a temp table. */
/* Preprocessor won't replace within quotes so have to use str(). */
declare @mscat nvarchar(12)
select @mscat = ltrim(str(convert(int, 0x0002)))
if (@precommand is not null)
 exec(@precommand)
/* Defined @isobject for save object type */
Declare @isobject varchar(256)
select @isobject= case @objectType when 1 then 'IsUserTable'
 when 2 then 'IsView'
 when 3 then 'IsTrigger'
 when 4 then 'IsProcedure' 
 when 5 then 'IsDefault' 
 when 6 then 'IsForeignKey'
 when 7 then 'IsScalarFunction'
 when 8 then 'IsInlineFunction'
 when 9 then 'IsPrimaryKey'
 when 10 then 'IsExtendedProc' 
 when 11 then 'IsReplProc'
 when 12 then 'IsRule'
 end
/* Create the select */
/* Use @isobject variable isstead of IsUserTable string */
EXEC(N'declare hCForEach cursor global for select ''['' + REPLACE(user_name(uid), N'']'', N'']]'') + '']'' + ''.'' + ''['' + 
REPLACE(object_name(id), N'']'', N'']]'') + '']'' from dbo.sysobjects o '
 + N' where OBJECTPROPERTY(o.id, N'''+@isobject+''') = 1 '+N' and o.category & ' + @mscat + N' = 0 '
 + @whereand)
declare @retval int
select @retval = @@error
if (@retval = 0)
 exec @retval = sp_MSforeach_worker @command1, @replacechar, @command2, @command3
if (@retval = 0 and @postcommand is not null)
 exec(@postcommand)
return @retval
GO

这样我们来测试一下:
 --获得所有的存储过程的脚本:
 EXEc sp_MSforeachObject @command1="sp_helptext '?' ",@objectType=4
 --获得所有的视图的脚本:
 EXEc sp_MSforeachObject @command1="sp_helptext '?' ",@objectType=2
 --比如在开发过程中,没一个用户都是自己的OBJECT OWNER,所以在真实的数据库时都要改为DBO:
 EXEc sp_MSforeachObject @command1="sp_changeobjectowner '?', 'dbo'",@objectType=1
 EXEc sp_MSforeachObject @command1="sp_changeobjectowner '?', 'dbo'",@objectType=2
 EXEc sp_MSforeachObject @command1="sp_changeobjectowner '?', 'dbo'",@objectType=3
 EXEc sp_MSforeachObject @command1="sp_changeobjectowner '?', 'dbo'",@objectType=4
 这样就非常方便的将每一个数据库对象改为DBO.
 
--
exec sp_helptext sp_msforeachtable 
Text 
--
create proc sp_MSforeachtable
    @command1 nvarchar(2000), @replacechar nchar(1) = N'?', @command2 nvarchar(2000) = null,
 @command3 nvarchar(2000) = null, @whereand nvarchar(2000) = null,
    @precommand nvarchar(2000) = null, @postcommand nvarchar(2000) = null
as
    /* This proc returns one or more rows for each table (optionally, matching @where), with each table defaulting to its own result set */
    /* @precommand and @postcommand may be used to force a single result set via a temp table. */
    /* Preprocessor won't replace within quotes so have to use str(). */
    declare @mscat nvarchar(12)
    select @mscat = ltrim(str(convert(int, 0x0002)))
    if (@precommand is not null) exec(@precommand)

    /* Create the select */
 exec(N'declare hCForEach cursor global for select ''['' + REPLACE(user_name(uid), N'']'', N'']]'') + '']'' + ''.'' + ''['' + REPLACE(object_name(id), N'']'', N'']]'') + '']'' from dbo.sysobjects o '
 + N' where OBJECTPROPERTY(o.id, N''IsUserTable'') = 1 ' + N' and o.category & ' + @mscat + N' = 0 '
 + @whereand)
    declare @retval int
    select @retval = @@error
    if (@retval = 0)
        exec @retval = sp_MSforeach_worker @command1, @replacechar, @command2, @command3

    if (@retval = 0 and @postcommand is not null)
        exec(@postcommand)

    return @retval

--
exec sp_helptext sp_msforeachdb 
Text 
--
/*
 * The following table definition will be created by SQLDMO at start of each connection.
 * We don't create it here temporarily because we need it in Exec() or upgrade won't work.
 */

create proc sp_MSforeachdb
    @command1 nvarchar(2000), @replacechar nchar(1) = N'?', @command2 nvarchar(2000) = null, @command3 nvarchar(2000) = null,
    @precommand nvarchar(2000) = null, @postcommand nvarchar(2000) = null
as
 set deadlock_priority low
 
    /* This proc returns one or more rows for each accessible db, with each db defaulting to its own result set */
    /* @precommand and @postcommand may be used to force a single result set via a temp table. */

    /* Preprocessor won't replace within quotes so have to use str(). */
    declare @inaccessible nvarchar(12), @invalidlogin nvarchar(12), @dbinaccessible nvarchar(12)
    select @inaccessible = ltrim(str(convert(int, 0x03e0), 11))
    select @invalidlogin = ltrim(str(convert(int, 0x40000000), 11))
    select @dbinaccessible = N'0x80000000' /* SQLDMODbUserProf_InaccessibleDb; the negative number doesn't work in convert() */

    if (@precommand is not null)
        exec(@precommand)

    declare @origdb nvarchar(128)
    select @origdb = db_name()

    /* If it's a single user db and there's an entry for it in sysprocesses who isn't us, we can't use it. */
 /* Create the select */
    exec(N'declare hCForEach cursor global for select name from master.dbo.sysdatabases d ' +
            N' where (d.status & ' + @inaccessible + N' = 0)' +
            N' and ((DATABASEPROPERTY(d.name, ''issingleuser'') = 0 and (has_dbaccess(d.name) = 1)) or ' +
            N' ( DATABASEPROPERTY(d.name, ''issingleuser'') = 1 and not exists ' +
            N' (select * from master.dbo.sysprocesses p where dbid = d.dbid and p.spid <> @@spid)))' )

    declare @retval int
    select @retval = @@error
    if (@retval = 0)
        exec @retval = sp_MSforeach_worker @command1, @replacechar, @command2, @command3

 if (@retval = 0 and @postcommand is not null)
 exec(@postcommand)
 declare @tempdb nvarchar(258)
 SELECT @tempdb = REPLACE(@origdb, N']', N']]')
 exec (N'use ' + N'[' + @tempdb + N']')
 return @retval