Question

我尝试了下面的声明，但它没有用。查询分析器返回“（0）行受影响”。好消息......它没有爆炸......坏消息......我不知道这个陈述有什么问题。

我想我正在使用SQL Server 2000.我还没有在我的演示数据库上尝试过该语句。第二个语句是将旧oillab（oillabid = 4）更新为新的oillab（oillabid = 9）。 oillabid映射到oillabstatus表中正在更改的oillabstatusid。

我想通过customerid更新oildatasetstatus表中的oildatasetstatusid。为了获得customerid，我需要从oildataset表中获取oildatasetid（映射到oildatasetstatus表）和samplepointid。 samplepointid映射到samplepoint表，该表还包含customersiteid。 customersiteid映射到包含customerid的customersite表。更新完成后，我需要更新oildataset表中的oillabid。我猜这必须使用两个语句（如下所示）。这些陈述看起来是正确的还是有任何明显的错误？无论如何在一个声明中做这两个更新？感谢。

update  oildatasetstatus set oildatasetstatusid = 
case 
       WHEN oildatasetstatusid = 5 THEN 16
            WHEN oildatasetstatusid = 6 THEN 17
            WHEN oildatasetstatusid = 7 THEN 18
            WHEN oildatasetstatusid = 8 THEN 18
            WHEN oildatasetstatusid = 9 THEN 18
            WHEN oildatasetstatusid = 10 THEN 19
               WHEN oildatasetstatusid = 11 THEN 20
End    
where oildatasetid in
(
select oildatasetstatusid from oildatasetstatus 
 inner join oildataset on oildataset.oildatasetid=oildatasetstatus.oildatasetid
where samplepoinid in
    (
    select samplepointid from samplepoint where customersiteid in
        (
        select customersiteid from customersite where customerid=2
        )
    )
)

update oildataset set oillabid=9 where oildatasetstatusid between 16 and 20

Answer 1

如何分解并测试您是否获得了正确的结果并逐步将它们组合在一起？

初始UPDATE的WHERE条件（编辑为INNER JOIN而不是SELECT INs）并且还选择了 oildatasetid而不是oildatasetstatusid ：

SELECT oildatasetid FROM oildatasetstatus
INNER JOIN oildataset
    ON oildataset.oildatasetid = oildatasetstatus.oildatasetid
INNER JOIN samplepoint
    ON oildatasetstatus.samplepoinid = samplepoint.samplepointid
INNER JOIN customersite
    ON samplepoint.customersiteid = customersite.customersiteid
WHERE customerid = 2;

这应该返回与查询相同的oildatasetid列表，但运行速度更快。

现在UPDATE语句：

UPDATE oildatasetstatus SET oildatasetstatusid = 
    CASE
        WHEN oildatasetstatusid = 5 THEN 16
        WHEN oildatasetstatusid = 6 THEN 17
        WHEN oildatasetstatusid = 7 THEN 18
        WHEN oildatasetstatusid = 8 THEN 18
        WHEN oildatasetstatusid = 9 THEN 18
        WHEN oildatasetstatusid = 10 THEN 19
        WHEN oildatasetstatusid = 11 THEN 20
    END
WHERE oildatasetid IN (
    SELECT oildatasetid FROM oildatasetstatus
    INNER JOIN oildataset
        ON oildataset.oildatasetid = oildatasetstatus.oildatasetid
    INNER JOIN samplepoint
        ON oildatasetstatus.samplepoinid = samplepoint.samplepointid
    INNER JOIN customersite
        ON samplepoint.customersiteid = customersite.customersiteid
    WHERE customerid = 2
);

除非绝对必要，否则我会避免BETWEEN：

UPDATE oildataset SET oillabid = 9 WHERE oildatasetstatusid >= 16 AND oildatasetstatusid <= 20;

通过从多个表中提取信息来更新表

1 个答案: