先停止sql服务

exec sp_detach_db @dbname='book'

--重建日志
exec sp_attach_single_file_db @dbname='book',
                              @physname='D:\Program Files\Microsoft SQL Server\MSSQL\Data\book_Data.MDF'

------解决方案--------------------
给个通过日志恢复列子:
SQL code
USE master

--创建数据库
CREATE DATABASE db
ON PRIMARY(
    NAME='db_data',
    FILENAME= 'c:\db_data.mdf')
LOG ON(
    NAME='db_log',
    FILENAME ='c:\db.ldf')
GO

--创建表
CREATE TABLE db.dbo.ta(id int)
INSERT db.dbo.ta SELECT id FROM sysobjects
GO
--做文件组备份
BACKUP DATABASE db TO DISK='c:\db.bak' WITH FORMAT

--备份后,再做数据处理
CREATE TABLE db.dbo.tb(id int)
INSERT db.dbo.tb SELECT id FROM sysobjects
GO

/*--下面演示了破坏数据文件的处理，这些操作在操作系统中进行

1. 停止SQL Server服务(msqlserver服务)
2. 删除文件 c:\db_data.ndf (模拟破坏)
3. 重新SQL Server服务,此时数据库DB置疑
--*/
GO

--下面演示了如何恢复数据
--首先要备份当前日志
BACKUP LOG db TO DISK='c:\db_log.bak' WITH FORMAT,NO_TRUNCATE
--利用文件组备份恢复破坏的文件
RESTORE DATABASE db FROM DISK='c:\db.bak' WITH NORECOVERY
--还原到日志点
RESTORE LOG db FROM DISK='c:\db_log.bak' WITH RECOVERY
--显示已经恢复的数据
SELECT COUNT(*) FROM db.dbo.ta
SELECT COUNT(*) FROM db.dbo.tb
GO

--删除测试
DROP DATABASE db

------解决方案--------------------
用dbcc checkdb检查一下数据库中是否存在分配错误和一致性错误。

如果存在，先修复这些错误。

dbcc checkdb ('数据库名', REPAIR_ALLOW_DATA_LOSS)

------解决方案--------------------
SQL code
清除日志：

 
DECLARE @LogicalFileName sysname,
        @MaxMinutes INT,
        @NewSize INT
USE     szwzcheck             -- 要操作的数据库名
SELECT  @LogicalFileName = 'szwzcheck_Log',  -- 日志文件名
@MaxMinutes = 10,               -- Limit on time allowed to wrap log.
        @NewSize = 20                  -- 你想设定的日志文件的大小(M)
-- Setup / initialize
DECLARE @OriginalSize int
SELECT @OriginalSize = size 
  FROM sysfiles
  WHERE name = @LogicalFileName
SELECT 'Original Size of ' + db_name() + ' LOG is ' + 
        CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + 
        CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'
  FROM sysfiles
  WHERE name = @LogicalFileName
CREATE TABLE DummyTrans
  (DummyColumn char (8000) not null)
DECLARE @Counter   INT,
        @StartTime DATETIME,
        @TruncLog  VARCHAR(255)
SELECT  @StartTime = GETDATE(),
        @TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY'
DBCC SHRINKFILE (@LogicalFileName, @NewSize)
EXEC (@TruncLog)
-- Wrap the log if necessary.
WHILE     @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time 
      AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = 
@LogicalFileName)  
      AND (@OriginalSize * 8 /1024) > @NewSize  
  BEGIN -- Outer loop.
    SELECT @Counter = 0
    WHILE  ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))
      BEGIN -- update
        INSERT DummyTrans VALUES ('Fill Log')  
        DELETE DummyTrans
        SELECT @Counter = @Counter + 1
      END   
    EXEC (@TruncLog)  
  END   
SELECT 'Final Size of ' + db_name() + ' LOG is ' +
        CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 
        CONVERT(VARCHAR(30),(size*8/1024)) + 'MB'
  FROM sysfiles 
  WHERE name = @LogicalFileName
DROP TABLE DummyTrans
SET NOCOUNT OFF
 
把szwzcheck换成你数