Question

我在SPROC中插入语句（简化），如下所示

SET ROWCOUNT 100

WHILE(1=1)
BEGIN

  INSERT INTO table1
  SELECT *
  FROM table2
  WHERE some_condition
  -- EDIT: Realized forgot to include this following vital line that is causing issue
  SET @var = @var + @@ROWCOUNT    

  -- @@ROWCOUNT now takes on a value of 1, which will cause the following IF check to fail even when no lines are inserted

  IF(@@ROWCOUNT = 0)
  BEGIN
    BREAK
  END

END

但问题是，在任何操作后，即使我的some_condition没有更多行，@@ROWCOUNT也等于1，而不是0。

如果返回的0行与我的some_condition匹配，我怎么能打破这个循环？

Answer 1

“set”语句创建的行数为1.您应该立即将@@ ROWCOUNT保存到@rowCount变量中并稍后使用该变量。

declare @rowCount int

WHILE(1=1)
BEGIN

  INSERT INTO table1
  SELECT *
  FROM table2
  WHERE some_condition
  -- EDIT: Realized forgot to include this following vital line that is causing issue
  SET @rowCount = @@ROWCOUNT
  SET @var = @var + @rowCount    

  -- @@ROWCOUNT now takes on a value of 1, which will cause the following IF check to fail even when no lines are inserted

  IF(@rowCount = 0)
  BEGIN
    BREAK
  END

END

此外，您可以通过将@rowCount初始设置为-1并将WHILE条件更改为@rowCount＆lt;＆gt;来简化操作。 0.将不再需要有条件的BREAK。

Answer 2

另一种解决方案。这将检查每次迭代以查看最后插入的记录的ID是否已更改。如果它没有改变，则表示没有添加该迭代的记录。

SET ROWCOUNT 100
declare @id int;
WHILE(1=1)

  INSERT INTO table1
  SELECT *
  FROM table2
  WHERE some_condition

  IF(@id= @@identity)
  BEGIN
    BREAK
  END
  set @id = @@identity;
END

Answer 3

尝试此解决方案：

第一个解决方案

在循环条件中使用@@ROWCOUNT。

SET ROWCOUNT 100

  INSERT INTO table1
  SELECT *
  FROM table2
  WHERE some_condition  


WHILE(@@ROWCOUNT > 0)
BEGIN

  INSERT INTO table1
  SELECT *
  FROM table2
  WHERE some_condition  

END

第二次解决

使用goto。

SET ROWCOUNT 100

WHILE(1=1)
BEGIN

  INSERT INTO table1
  SELECT *
  FROM table2
  WHERE some_condition

  IF(@@ROWCOUNT = 0)
  BEGIN
    goto label
  END

END

label1:
print 'After lopp'

Answer 4

我认为您应该使用select将@@rowcount变为变量。试试这个：

declare @number_of_rows int    

SET ROWCOUNT 100

WHILE(1=1)
BEGIN

  INSERT INTO table1
  SELECT *
  FROM table2
  WHERE some_condition

  SELECT @number_of_rows=@@ROWCOUNT

  IF (@number_of_rows = 0)
  BEGIN
     BREAK
  END
END

Answer 5

实施类似于Moho的解决方案，但使用SELECT代替SET来存储@@ROWCOUNT。

当@@ ROWCOUNT = 0时，TSQL中断循环

5 个答案: