SQL Server - 按外观替换字符串答案

【问题标题】：SQL Server - replace string by appearanceSQL Server - 按外观替换字符串
【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

标签： sql sql-server replace

【解决方案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);

【讨论】：