sqlserver 存储过程,浅析SQLServer一个没有公开的存储过程

浅析SQLServer一个没有公开的存储过程 - 应用软件 - 电脑教程网

浅析SQLServer一个没有公开的存储过程

日期:2006-09-01   荐:
·一个SQL存储过程·经验总结:ASP与存储过程解析·SQL Server编写存储过程小工具·如何在SQL存储过程中处理错误·收藏几段SQL Server语句和存储过程·asp 存储过程的使用·sql server2000中怎么对存储过程进行加·MySQL 5.0新特性教程 存储过程·使用C#创建SQL Server的存储过程·ASP中使用存储过程   从SQLSERVER6.5开始,MS提供了一个非常有用的系统存储过程sp_MSforeachtable和sp_MSforeachDB;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,我们就必须这样写游标:  DECLARE @TableName varchar(255)  DECLARE @ExeSQL varchar(4000)    DECLARE Table_Cursor CURSOR FOR SELECT [name] FROM sysobjects WHERE xtype='U'    OPEN Table_Cursor  FETCH NEXT FROM Table_Cursor INTO @TableName    WHILE(@@FETCH_STATUS=0)  BEGIN   PRINT @TableName   SELECT @ExeSQL='DBCC CHECKTABLE(''' @TableName ''')'   EXEC(@EXESQL)  FETCH NEXT FROM Table_Cursor INTO @TableName  END    CLOSE Table_Cursor  DEALLOCATE Table_Cursor  GO    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('?')"  大家可以看出这样就更加简洁(虽然在后台也是通过游标来处理的),下面我们就仔细分析一下sp_MSforeachtable这个存储过程:    我们看看sp_MSforeachtable详细的CODE:  USE MASTER   GO  SP_HELPTEXT sp_MSforeachtable    --下面时sp_MSforeachtable的原始代码    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    这个系统存储过程有7个参数:   @command1 nvarchar(2000), --第一条运行的T-SQL指令   @replacechar nchar(1) = N'?',  --指定的占位符号    @command2 nvarchar(2000) = null,--第二条运行的T-SQL指令    @command3 nvarchar(2000) = null, --第三条运行的T-SQL指令   @whereand nvarchar(2000) = null, --可选条件来选择表   @precommand nvarchar(2000) = null, --在表前执行的指令   @postcommand nvarchar(2000) = null --在表后执行的指令      所以上面的语句也可以这样写:  EXEC sp_MSforeachtable @command1="print '?'",       @command2= "DBCC CHECKTABLE('?')"    了解参数以后,就让我们做几个实列吧:  1.获得每个表的记录数和容量:  EXEC sp_MSforeachtable @command1="print '?'",       @command2="sp_spaceused '?'",       @command3= "SELECT count(*) FROM ? "    2.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!'"      sp_MSforeachDB除了@whereand外,和sp_MSforeachtable的参数是一样的,我们可以通过这个存储过程检测所有的数据库,比如:  1.获得所有的数据库的存储空间:      EXEC sp_MSforeachdb @command1="print '?'",                       @command2="sp_spaceused "  2.检查所有的数据库      EXEC sp_MSforeachdb @command1="print '?'",                        @command2="DBCC CHECKDB (?) "     有了上面的分析,我们可以建立自己的sp_MSforeachObject:  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:  1.获得所有的存储过程的脚本:       EXEc sp_MSforeachObject @command1="sp_helptext '?' ",@objectType=4  2.获得所有的视图的脚本:       EXEc sp_MSforeachObject @command1="sp_helptext '?' ",@objectType=2  3.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.
标签: