Question

我正在使用C＃.NET开发一个多项选择考试生成器。每次报告时，都会在数据库中随机挑选问题，随机选择随机选择的问题。我可以做随机问题部分，但我无法改变选择。

我有一个像这样的行的表：

-----------------------------------------------------
|question|answer|distractor1|distractor2|distractor3|
|q1      |ansq1 |d1q1       |d2q1       |d2q1       |
-----------------------------------------------------

我想要的是将答案， distractor1 和 distractor3 列的值改组。例如：

-----------------------------------------------------
|question|answer|distractor1|distractor2|distractor3|
|q1      |d3q1  |d2q1        |d1q1       |ansq1     |
-----------------------------------------------------

这可以使用SQL查询吗？

Answer 1

以下是使用Dynamic Sql

的一个技巧

WHILE 1 = 1
    BEGIN
        DECLARE @answer SYSNAME = (SELECT TOP 1 COLUMN_NAME
            FROM   INFORMATION_SCHEMA.columns
            WHERE  TABLE_NAME = 'yourtable' AND COLUMN_NAME NOT IN ( 'question', 'answer')
            ORDER  BY Newid())
        DECLARE @distractor1 SYSNAME = (SELECT TOP 1 COLUMN_NAME
            FROM   INFORMATION_SCHEMA.columns
            WHERE  TABLE_NAME = 'yourtable' AND COLUMN_NAME NOT IN ( 'question', @answer, 'distractor1' )
            ORDER  BY Newid())
        DECLARE @distractor2 SYSNAME = (SELECT TOP 1 COLUMN_NAME
            FROM   INFORMATION_SCHEMA.columns
            WHERE  TABLE_NAME = 'yourtable' AND COLUMN_NAME NOT IN ( 'question', @answer, 'distractor2', @distractor1 )
            ORDER  BY Newid())
        DECLARE @distractor3 SYSNAME = (SELECT TOP 1 COLUMN_NAME
            FROM   INFORMATION_SCHEMA.columns
            WHERE  TABLE_NAME = 'yourtable' AND COLUMN_NAME NOT IN ( 'question', @answer, 'distractor3', @distractor2, @distractor1 )
            ORDER  BY Newid())

        IF @distractor1 IS NOT NULL
            AND @distractor2 IS NOT NULL
            AND @distractor3 IS NOT NULL
            AND @answer IS NOT NULL
        BREAK
    END
--select @distractor1,@distractor2,@distractor3
exec( 'update yourtable set answer = '+@answer+', distractor1 = '+@distractor1+', distractor2 = '+@distractor2+', distractor3 = '+@distractor3)

select * from yourtable

每行随机播放列值

1 个答案: