Question

我有一个表ABSENCE，它有40个员工ID，需要从表变量中添加两列，作为参考表。对于每个emp id，我需要从表变量中随机分配值。这是我在没有随机化的情况下尝试的代码：

USE TSQL2012;
GO
DECLARE @MAX SMALLINT;
DECLARE @MIN SMALLINT;
DECLARE @RECODE SMALLINT;
DECLARE @RE CHAR(100);

DECLARE @rearray table (recode smallint,re char(100));
insert into @rearray values (100,'HIT BY BEER TRUCK')
,(200,'BAD HAIR DAY')
,(300,'ASPIRIN OVERDOSE')
,(400,'MAKEUP DISASTER')
,(500,'GOT LOCKED IN THE SALOON')

DECLARE @REFCURSOR AS CURSOR;
SET @REFCURSOR = CURSOR FOR  
SELECT RECODE,RE FROM @REARRAY; 
OPEN @REFCURSOR; 

SET @MAX = (SELECT DISTINCT @@ROWCOUNT FROM ABSENCE); 
SET @MIN = 0; 
ALTER TABLE ABSENCE ADD CODE SMALLINT, REASONING CHAR(100);

WHILE (@MIN <= @MAX)
BEGIN
        FETCH NEXT FROM @REFCURSOR INTO @RECODE,@RE; 
        INSERT INTO ABSENCE (CODE, REASONING) VALUES (@RECODE,@RE);
        SET @MIN+=1;
END
CLOSE @REFCURSOR
DEALLOCATE @REFCURSOR 

SELECT EMPID,CODE,REASONING FROM ABSENCE

虽然我只插入两列，但是它试图插入empid（已经填充）并且因为它不能为NULL，插入失败。

另外，如何随机化REARRAY表变量中的值以将它们插入到ABSENCE表中？

Answer 1

由于这是一个小型数据集，因此一种方法可能是CROSS APPLY采用SELECT TOP(1) ... FROM @rearray ORDER BY NEWID()方法。这将基本上将ABSENCE表与您的引用表一起加入UPDATE语句中，每次在连接中选择一个随机行。完整的，它看起来像：

UPDATE ABSENCE
SET col1 = x1.recode, col2 = x2.recode
FROM ABSENCE a
    CROSS APPLY (SELECT TOP(1) * FROM @rearray ORDER BY NEWID()) x1(recode, re)
    CROSS APPLY (SELECT TOP(1) * FROM @rearray ORDER BY NEWID()) x2(recode, re)

将随机文本插入参考表变量的列中

1 个答案: