在 SQL Server 2008 中执行 while 循环

Do while loop in SQL Server 2008(在 SQL Server 2008 中执行 while 循环)

问题描述

SQL server 2008有没有实现do while循环的方法?

我不确定 MS SQL Server 2008 中的 DO-WHILE，但您可以更改 WHILE 循环逻辑，以便像 DO-WHILE 循环一样使用.

示例取自此处:http://blog.sqlauthority.com/2007/10/24/sql-server-simple-example-of-while-loop-with-continue-and-break-keywords/

1. WHILE 循环示例

   DECLARE @intFlag INT设置@intFlag = 1同时 (@intFlag <=5)开始打印@intFlagSET @intFlag = @intFlag + 1结尾走

   结果集:

   12345

2. 带有 BREAK 关键字的 WHILE 循环示例

   DECLARE @intFlag INT设置@intFlag = 1同时 (@intFlag <=5)开始打印@intFlagSET @intFlag = @intFlag + 1如果@intFlag = 4休息;结尾走

   结果集:

   123

3. 带有 CONTINUE 和 BREAK 关键字的 WHILE 循环示例

   DECLARE @intFlag INT设置@intFlag = 1同时 (@intFlag <=5)开始打印@intFlagSET @intFlag = @intFlag + 1继续;IF @intFlag = 4 -- 这将永远不会执行休息;结尾走

   结果集:

   12345

但是尽量在数据库级别避免循环.参考.

Is there any method for implement do while loop in SQL server 2008?

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.

这篇关于在 SQL Server 2008 中执行 while 循环的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！