在SQL Server 2008中执行while循环 [英] Do while loop in SQL Server 2008

问题描述

在SQL Server 2008中是否有实现do while循环的方法?

解决方案

我不确定MS SQL Server 2008中的DO-WHILE，但是您可以更改WHILE循环逻辑，以便像DO-WHILE循环那样使用. /p>

示例摘自此处: 解决方案

I am not sure about DO-WHILE IN MS SQL Server 2008 but you can change your WHILE loop logic, so as to USE like DO-WHILE loop.

Examples are taken from here: http://blog.sqlauthority.com/2007/10/24/sql-server-simple-example-of-while-loop-with-continue-and-break-keywords/

1. Example of WHILE Loop

   DECLARE @intFlag INT
   SET @intFlag = 1
   WHILE (@intFlag <=5)
   BEGIN
       PRINT @intFlag
       SET @intFlag = @intFlag + 1
   END
   GO
   

   ResultSet:

   1
   2
   3
   4
   5
   

2. Example of WHILE Loop with BREAK keyword

   DECLARE @intFlag INT
   SET @intFlag = 1
   WHILE (@intFlag <=5)
   BEGIN
       PRINT @intFlag
       SET @intFlag = @intFlag + 1
       IF @intFlag = 4
           BREAK;
   END
   GO
   

   ResultSet:

   1
   2
   3
   

3. Example of WHILE Loop with CONTINUE and BREAK keywords

   DECLARE @intFlag INT
   SET @intFlag = 1
   WHILE (@intFlag <=5)
   BEGIN
       PRINT @intFlag
       SET @intFlag = @intFlag + 1
       CONTINUE;
       IF @intFlag = 4 -- This will never executed
           BREAK;
   END
   GO
   

   ResultSet:

   1
   2
   3
   4
   5
   

But try to avoid loops at database level. Reference.

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