Sql Server在while循环期间打印受影响的行

Question

我有一个在sql server 2008上运行的存储过程，循环遍历大约5000万行的表，每天有一天删除记录（每天大约25,000条记录）。我希望能够在流程通过打印语句运行到消息窗口时观察到这种情况。我希望每次发生一天的删除操作时都能看到一条消息。有没有办法做这样的事情？该过程大致布局是这样的：

WHILE EXISTS(<query statement>) 
BEGIN 

BEGIN TRAN 

DELETE 
FROM <table> 
WHERE <condition> 
AND <condition> 

--need some sort of "rows affected" statement here 

COMMIT 

END 

Answer 1

不幸的是，PRINT语句输出被缠绕起来，而不是立即写入到输出。一个办法解决这是使用RAISERROR这样的：

RAISERROR ('MY MESSAGE', 0, 1) WITH NOWAIT 

特别是你想要的东西：

DECLARE @Msg VARCHAR(200) 

    WHILE EXISTS(<query statement>) 
    BEGIN 
    BEGIN TRAN 

    DELETE 
    FROM <table> 
    WHERE <condition> 
    AND <condition> 

    SELECT @Msg = CAST(@@ROWCOUNT AS VARCHAR(10)) + ' rows affected' 
    RAISERROR (@Msg, 0, 1) WITH NOWAIT 

    COMMIT 
    END 

我也倾向于在消息中包含当前时间，所以我可以记录与时间进度。

Answer 2

比select @@ rowcount更复杂吗？

Answer 3

如何使用OUTPUT子句？你可以从存储过程写入SQL Server控制台吗？

就像在触发器中一样，您的手中有一个“已删除”伪表，其中包含正在删除的行及其所有列。

WHILE EXISTS(<query statement>) 
BEGIN 
    BEGIN TRAN 

    DELETE FROM <table> 
    OUTPUT deleted.ID, deleted.TimeStamp -- or whatever 
    WHERE <condition> 
    AND <condition> 

    COMMIT 

END 

Answer 4

我以前做类似这样的东西，因为在那里缠绕了打印是没有多大用处，但我发现，在命令行实用程序osql输出他们立即，所以我写的存储过程，并把它称为从一个批处理文件，而让我看到进展。

Answer 5

执行以下操作：

DECLARE @queryCount AS INT, @start AS INT, @stop as INT, @table as varchar(max) 

SELECT @start = cnt(*) as a FROM <table> 

SELECT @queryCount = cnt(*) 
    FROM <table> 
    WHERE <condition> 
    AND <condition> 

DELETE 
    FROM <table> 
    WHERE <condition> 
    AND <condition> 

SELECT @stop = cnt(*) as a FROM <table> 

PRINT(convert(varchar(max), @queryCount) + ' rows deleted from ' + convert(varchar(max), @table)) 

如果你想验证，您可以在下面的代码抛出。

PRINT('Rows at start: ' + convert(varchar(max), @start)) 
PRINT('Rows at end: ' + convert(varchar(max), @stop)) 
PRINT('Row difference: ' + convert(varchar(max), @start - @stop)) 

警告：如果在发生这种情况时数据库可能会影响行，则可能会看到差异。

Answer 6

你可以做这样的事情来遍历每个行

  declare @ii (id int) table 

    -- for batchchunk operations  

      declare @numTransactions as int = 0,   
      @totalRowsInserted as int = 0,   
      @chunksize int = 0,   
      @printnow varchar(1000)  


     --does the initial insert into the table  
      select * from #table  
      SET @numTransactions =@@rowcount  
      SET @printnow = 'Should Insert :'+cast(@numTransactions as varchar)+ ' rows into the table.'   
      exec db.printNow @printnow;  -- shortened proc 

      BEGIN   
      INSERTCHUNKS:   

      SET ROWCOUNT @Batchsize     



      insert into table     
      (     
      type_id,     
      parent_id,     
      created_by_user_id,     
      created_at,     
      updated_by_user_id,     
      updated_at,     
      created_by_system_id,     
      updated_by_system_id,     
      is_deleted     
      )     
      output inserted.id into @ii(id)     

      select     
      1,--party_type_id     
     NULL,--parent_party_id     
     @user_id, --created_by_user_id     
     case when created_at is NULL then getdate() else created_at end ,        

     NULL , --updated_by_user_id     
     case when updated_at is NULL then getdate() else updated_at end, -- 
     updated_at     
     case when created_by_system_id is null then 292 else 0 end, --created_by_system_id     
      updated_by_system_id,--updated_by_system_id     \ 
      0 --is_deleted     
     from     
     #table   
     order by id asc    
     OFFSET    
     @TotalRowsInserted ROWS   
     FETCH NEXT @batchsize ROWS ONLY  
     set @chunksize =@@rowcount    
      IF @chunksize > 0  
      BEGIN    
     set @totalRowsInserted = @totalRowsInserted + @chunksize    
      SET @printnow = 'Batch done: ' + 
      cast(@chunksize as varchar) + ' rows in Batch ; '   
      + cast(@totalRowsInserted as varchar) + ' total inserted so far 
      into the table.'    exec db.printnow @printnow;    

      waitfor delay '00:00:01'   
      GOTO INSERTCHUNKS   
      END   
      SET ROWCOUNT 0;  
      END