Oracle - 按外观替换字符串

Question

我有一个有趣的问题，如果你能分享你的想法......我改变了一些数据，但结构是一样的

create table TestReplace (Description varchar2(500), ParamValue1 number, ParamValue2 number, ParamValue3 number);
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);

COMMIT;

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ParamValue1 列的值，第二个词 {param} 与列 ParamValue2 的值，第三个与列 ParamValue3 的值

我尝试过这样的事情......

select CASE WHEN ParamValue1 IS NULL 
    THEN Description 
   ELSE 
    substr(Description, 1, INSTR(Description,'{param}', 1, 1) - 1) || ParamValue1 ||
        CASE WHEN ParamValue2 IS NULL 
            THEN substr(Description, INSTR(Description,'{param}', 1, 1) + 7, LENGTH(Description) - INSTR(Description,'{param}', 1, 1) + 6)
        WHEN ParamValue2 IS NOT NULL THEN
            substr(Description, INSTR(Description,'{param}', 1, 1) + 7, INSTR(Description,'{param}', 1, 2) + 6 - INSTR(Description,'{param}', 1, 1) + 6) || ParamValue2
       END
    END
   END
from TestReplace

但这并没有把我带到任何地方，而且我个人认为这在更大的行集上不会很好/很快

那么我该如何完成这个文本替换呢？

Answer 1

使用 REGEXP_REPLACE 的嵌套调用：

SELECT REGEXP_REPLACE(REGEXP_REPLACE(REGEXP_REPLACE(DESCRIPTION, 
                                                    '{param}', PARAMVALUE1, 1, 1),
                                     '{param}', PARAMVALUE2, 1, 1),
                      '{param}', PARAMVALUE3, 1, 1)
  FROM TESTREPLACE

dbfiddle here