SQL Server - 按外观替换字符串

Posted 2023-03-11

【中文标题】SQL Server - 按外观替换字符串

【英文标题】：SQL Server - replace string by appearance

【发布时间】：2020-05-26 19:08:31

【问题描述】：

有个小问题……这是测试数据

CREATE TABLE #TestReplace (
    Description NVARCHAR(500)
    ,ParamValue1 INT
    ,ParamValue2 INT
    ,ParamValue3 INT
    );

INSERT INTO #TestReplace (Description)
VALUES ('This sentence has no parameteres, and it should be shown like this');

INSERT INTO #TestReplace (
    Description
    ,ParamValue1
    )
VALUES (
    'This sentence has only one parametere, and it should be shown right here param with rest of text'
    ,100
    );

INSERT INTO #TestReplace (
    Description
    ,ParamValue1
    ,ParamValue2
    )
VALUES (
    'This sentence has two parameteres, one here param and one here param, show full sentence'
    ,100
    ,200
    );

INSERT INTO #TestReplace (
    Description
    ,ParamValue1
    ,ParamValue2
    ,ParamValue3
    )
VALUES (
    'This sentence has all parameteres, here param and here param and there param'
    ,100
    ,200
    ,300
    );

在我的句子中，我有时会或从不出现单词param ...和列ParamValue1、ParamValue2、ParamValue3 ...我如何将第一次出现的单词param替换为列ParamValue1 的值，第二个字param 与列ParamValue2 的值和第三个与列ParamValue3 的值...我无法将字param 更改为param1、param2 和@ 987654335@ 并进行简单替换

到目前为止，我设法只替换了第一次出现...

SELECT CASE 
        WHEN CHARINDEX('param', DESCRIPTION) > 0
            THEN STUFF(DESCRIPTION, CHARINDEX('param', DESCRIPTION), LEN('param'), ParamValue1)
        ELSE DESCRIPTION
        END
FROM #TestReplace

这在 Oracle 中很容易管理 (Oracle - replace string by appearance)

【问题讨论】：

SQL Server 本身不支持 REGEX，因此不支持 REGEX 替换。如果您确实想要这样的东西，您可能需要查看 CLR 函数。

您的 SQL Server 版本是多少？

目前在 Microsoft SQL Server 2012 上，但可以根据需要进行更新

【参考方案1】：

您可以使用APPLY 将它们链接在一起：

SELECT COALESCE(v3.DESCRIPTION, v2.DESCRIPTION, v1.DESCRIPTION, tr.DESCRIPTION)
FROM #TestReplace tr CROSS APPLY
     (VALUES (CASE WHEN tr.Description LIKE '%param%'
                   THEN STUFF(tr.DESCRIPTION, CHARINDEX('param', tr.DESCRIPTION), LEN('param'), tr.ParamValue1)
              END)
     ) v1(description) CROSS APPLY
     (VALUES (CASE WHEN v1.Description LIKE '%param%'
                   THEN STUFF(v1.DESCRIPTION, CHARINDEX('param', v1.DESCRIPTION), LEN('param'), tr.ParamValue2)
              END)
     ) v2(description) CROSS APPLY
     (VALUES (CASE WHEN v2.Description LIKE '%param%'
                   THEN STUFF(v2.DESCRIPTION, CHARINDEX('param', v2.DESCRIPTION), LEN('param'), ParamValue3)
              END)
     ) v3(description);