DB太大？一键帮你收缩所有DB文件大小（Shrink Files for All Databases in SQL Server）

本文介绍一个简单的SQL脚本，实现收缩整个Microsoft SQL Server实例所有非系统DB文件大小的功能。

作为一个与SQL天天打交道的程序猿，经常会遇到DB文件太大，把空间占满的情况：

而对于开发测试人员来说，如果DB数据不是特别重要的话，不会特意扩大磁盘空间，而是直接利用SQL的Shrink File功能缩小DB文件大小，详见：https://docs.microsoft.com/en-us/sql/relational-databases/databases/shrink-a-file。

这里介绍一个脚本，支持一键收缩整个SQL Server实例上所有非系统DB文件大小。

脚本支持功能和相关逻辑如下：

• 五个系统DB（master、model、msdb、tempdb、Resource）不会执行Shrink File操作；
• 如果DB的Recovery Model是FULL或者BULK_LOGGED，会自动改成SIMPLE，Shrink File操作后再改回原来的；
• 只会对DB状态为ONLINE的DB进行Shrink File操作；
• DB的所有文件，包括数据文件和日志文件都会被执行收缩操作（Shrink Database Data Files & Shrink Database Log Files）；
• 执行SQL脚本的用户需要有sysadmin或者相关数据库的DBO权限。

脚本如下：

-- Created by Bob from http://www.cnblogs.com/lavender000/
use master
DECLARE dbCursor CURSOR for select name from [master].[sys].[databases] where state = 0 and is_in_standby = 0;
DECLARE @dbname NVARCHAR(255)
DECLARE @recoveryModel NVARCHAR(255)
DECLARE @tempTSQL NVARCHAR(255)
DECLARE @dbFilesCursor CURSOR
DECLARE @dbFile NVARCHAR(255)
DECLARE @flag BIT

OPEN dbCursor
FETCH NEXT FROM dbCursor INTO @dbname

WHILE @@FETCH_STATUS = 0
BEGIN
    if((@dbname <> 'master') and (@dbname <> 'model') and (@dbname <> 'msdb') and (@dbname <> 'tempdb') and (@dbname <> 'Resource'))
    begin
        print('')
        print('Database [' + @dbname + '] will be shrinked log...')
        SET @flag = 1
        SET @recoveryModel = (SELECT recovery_model_desc FROM sys.databases WHERE name = @dbname)
        if((@recoveryModel = 'FULL') or (@recoveryModel = 'BULK_LOGGED'))
        begin
            SET @tempTSQL = (select CONCAT('ALTER DATABASE [', @dbname, '] SET RECOVERY SIMPLE with no_wait'))
            EXEC sp_executesql @tempTSQL
            if (@@ERROR = 0)
            begin
                print('    Database [' + @dbname + '] recovery model has been changed to ''SIMPLE''.')
                SET @flag = 1
            end
            else
            begin
                print('Database [' + @dbname + '] recovery model failed to be changed to ''SIMPLE''.')
                SET @flag = 0
            end
        end

        if(@flag = 1)
        begin
            SET @tempTSQL = (select CONCAT('use [', @dbname, ']'))
            EXEC sp_executesql @tempTSQL            
            SET @dbFilesCursor = CURSOR for select sys.master_files.name from sys.master_files, [master].[sys].[databases] where databases.name = @dbname and databases.database_id = sys.master_files.database_id
            open @dbFilesCursor
            FETCH NEXT FROM @dbFilesCursor INTO @dbFile
            WHILE @@FETCH_STATUS = 0
            BEGIN
                SET @tempTSQL = (select CONCAT('use [', @dbname, '] DBCC SHRINKFILE (N''', @dbFile, ''') with NO_INFOMSGS'))
                EXEC sp_executesql @tempTSQL
                if(@@ERROR = 0)    print('        Database file [' + @dbFile + '] has been shrinked log successfully.')
                FETCH NEXT FROM @dbFilesCursor INTO @dbFile
            END
            CLOSE @dbFilesCursor
            DEALLOCATE @dbFilesCursor

            if(@recoveryModel <> 'SIMPLE')
            begin
                -- Finally changed back
                SET @tempTSQL = (select CONCAT('ALTER DATABASE [', @dbname, '] SET RECOVERY ', @recoveryModel, ' with no_wait'))
                EXEC sp_executesql @tempTSQL
                if (@@ERROR = 0)
                begin
                    print('    Database [' + @dbname + '] recovery model has been changed back to ''' + @recoveryModel + '''')
                end
                else 
                begin
                    print('    Database [' + @dbname + '] recovery model failed to be changed back to ''' + @recoveryModel + '''')
                end
            end
        end
    end
FETCH NEXT FROM dbCursor INTO @dbname
END

CLOSE dbCursor
DEALLOCATE dbCursor

执行完效果如下：

Note：

• 如果不放心使用，可提前备份相关数据库；
• 使用前请仔细阅读脚本支持功能和相关逻辑，如与自己需求不符，请不要使用该脚本，或者请根据自己需求自行修改脚本；
• 脚本为简易脚本，仅用于测试学习，可能有BUG，不可生产环境使用，如有错误，请留言。

更新：该脚本在SQL Server 2008R2上执行可能会报如下错误：

'CONCAT' is not a recognized built-in function name.

由于脚本中使用了CONCAT函数，该函数是TSQL在SQL Server 2012中新引入的函数，具体详见：https://docs.microsoft.com/en-us/sql/t-sql/functions/concat-transact-sql。

因此如果想在SQL Server 2012以下版本中使用的话需要把CONCAT函数改成string +方法，具体如下：

-- Created by Bob from http://www.cnblogs.com/lavender000/
use master
DECLARE dbCursor CURSOR for select name from [master].[sys].[databases] where state = 0 and is_in_standby = 0;
DECLARE @dbname NVARCHAR(255)
DECLARE @recoveryModel NVARCHAR(255)
DECLARE @tempTSQL NVARCHAR(255)
DECLARE @dbFilesCursor CURSOR
DECLARE @dbFile NVARCHAR(255)
DECLARE @flag BIT

OPEN dbCursor
FETCH NEXT FROM dbCursor INTO @dbname

WHILE @@FETCH_STATUS = 0
BEGIN
    if((@dbname <> 'master') and (@dbname <> 'model') and (@dbname <> 'msdb') and (@dbname <> 'tempdb') and (@dbname <> 'Resource'))
    begin
        print('')
        print('Database [' + @dbname + '] will be shrinked log...')
        SET @flag = 1
        SET @recoveryModel = (SELECT recovery_model_desc FROM sys.databases WHERE name = @dbname)
        if((@recoveryModel = 'FULL') or (@recoveryModel = 'BULK_LOGGED'))
        begin
            SET @tempTSQL = ('ALTER DATABASE [' + @dbname + '] SET RECOVERY SIMPLE with no_wait')
            EXEC sp_executesql @tempTSQL
            if (@@ERROR = 0)
            begin
                print('    Database [' + @dbname + '] recovery model has been changed to ''SIMPLE''.')
                SET @flag = 1
            end
            else
            begin
                print('Database [' + @dbname + '] recovery model failed to be changed to ''SIMPLE''.')
                SET @flag = 0
            end
        end

        if(@flag = 1)
        begin
            SET @tempTSQL = ('use [' + @dbname + ']')
            EXEC sp_executesql @tempTSQL            
            SET @dbFilesCursor = CURSOR for select sys.master_files.name from sys.master_files, [master].[sys].[databases] where databases.name = @dbname and databases.database_id = sys.master_files.database_id
            open @dbFilesCursor
            FETCH NEXT FROM @dbFilesCursor INTO @dbFile
            WHILE @@FETCH_STATUS = 0
            BEGIN
                SET @tempTSQL = ('use [' + @dbname + '] DBCC SHRINKFILE (N''' + @dbFile + ''') with NO_INFOMSGS')
                EXEC sp_executesql @tempTSQL
                if(@@ERROR = 0)    print('        Database file [' + @dbFile + '] has been shrinked log successfully.')
                FETCH NEXT FROM @dbFilesCursor INTO @dbFile
            END
            CLOSE @dbFilesCursor
            DEALLOCATE @dbFilesCursor

            if(@recoveryModel <> 'SIMPLE')
            begin
                -- Finally changed back
                SET @tempTSQL = ('ALTER DATABASE [' + @dbname + '] SET RECOVERY ' + @recoveryModel + ' with no_wait')
                EXEC sp_executesql @tempTSQL
                if (@@ERROR = 0)
                begin
                    print('    Database [' + @dbname + '] recovery model has been changed back to ''' + @recoveryModel + '''')
                end
                else 
                begin
                    print('    Database [' + @dbname + '] recovery model failed to be changed back to ''' + @recoveryModel + '''')
                end
            end
        end
    end
FETCH NEXT FROM dbCursor INTO @dbname
END

CLOSE dbCursor
DEALLOCATE dbCursor

给大家带来的不变深表歉意。

[原创文章，转载请注明出处，仅供学习研究之用，如有错误请留言，谢谢支持]

[原站点：http://www.cnblogs.com/lavender000/p/6882741.html，来自永远薰薰]