Question

我对以下代码有两个问题：

UPDATE HRBI SET HRBI.PayGroupRegionCode = IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'Japan JPN', 'APJ',
IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'Taiwan TWN', 'APJ',
IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'China CNA', 'APJ',
IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'Australia AUS', 'APJ',
IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'Singapore SGP', 'APJ',
IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'Thailand THA', 'APJ',
IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'Luxembourg LUX','EMEA',
IIF(HRBI.PayGroupRegionCode = 'UNK' AND HRBI.CompensationGradeProfile = 'Romania ROU', 'EMEA',HRBI.PayGroupRegionCode))))))));

如果没有满足任何条件，false条件是否返回PayGroupRegionCode中的默认值（列中已有的值）？
还有其他/更好的方式来写这个吗？

Answer 1

是
考虑Switch而不是嵌套的IIf表达式。还可以使用模式CompensationGradeProfile IN (<list of values>)

UPDATE HRBI
SET HRBI.PayGroupRegionCode =
    Switch
        (
            HRBI.CompensationGradeProfile IN
                    (
                        'Japan JPN',
                        'Taiwan TWN',
                        'China CNA',
                        'Australia AUS',
                        'Singapore SGP',
                        'Thailand THA'
                    ), 'APJ',
            HRBI.CompensationGradeProfile IN
                    (
                        'Luxembourg LUX',
                        'Romania ROU'
                    ), 'EMEA',
            True, HRBI.PayGroupRegionCode
        )
WHERE HRBI.PayGroupRegionCode = 'UNK';

Answer 2

由于您要检查PayGroupRegionCode中的值是否已修复（"UNK"），因此您可以将其移至查询的WHERE子句。

现在，让我们简化一下：

UPDATE HRBI 
SET PayGroupRegionCode = IIF(CompensationGradeProfile = 'Japan JPN', 'APJ',
IIF(CompensationGradeProfile = 'Taiwan TWN', 'APJ',
IIF(CompensationGradeProfile = 'China CNA', 'APJ',
IIF(CompensationGradeProfile = 'Australia AUS', 'APJ',
IIF(CompensationGradeProfile = 'Singapore SGP', 'APJ',
IIF(CompensationGradeProfile = 'Thailand THA', 'APJ',
IIF(CompensationGradeProfile = 'Luxembourg LUX','EMEA',
IIF(CompensationGradeProfile = 'Romania ROU', 'EMEA', HRBI.PayGroupRegionCode))))))))
where PayGroupRegionCode = 'UNK';

现在，鉴于您只更新了两个值，我认为最简单的方法是使用两个不同的更新查询（更易于阅读和易于运行）：

UPDATE HRBI
SET payGroupRegionCode = 'APJ'
WHERE PayGroupRegionCode = 'UNK'
  AND CompensationGradeProfile IN ('Japan JPN', 'Taiwan TWN', 'China CNA', 
                                   'Australia AUS', 'Singapore SGP');
UPDATE HRBI
SET payGroupRegionCode = 'EMEA'
WHERE PayGroupRegionCode = 'UNK'
  AND CompensationGradeProfile IN ('Luxembourg LUX','Romania ROU');

请注意，由于您没有使用多个表，因此可以在查询（查询）的字段列表中省略表名。

替代方案（未经测试）

自从我上次使用Access以来已经有一段时间了，但也许你可以试试这个：

UPDATE HRBI
SET payGroupRegionCode = IIF(
        CompensationGradeProfile IN ('Japan JPN', 'Taiwan TWN', 'China CNA', 
                                     'Australia AUS', 'Singapore SGP'),
        'APJ',
        IIF(
            CompensationGradeProfile IN ('Luxembourg LUX','Romania ROU'), 
            'EMEA', 
            PayGroupRegionCode
        )
    )
WHERE PayGroupRegionCode = 'UNK';

有哪些基于两个条件更新列数据的有用方法？

2 个答案: