Question

示例数据：

[{url: bing.com},
{url: bing.com/search?q=test}, 
{url: bing.com/efesdf+sdsdksd}]

我想在＆＃39;之前返回所有网址字符串？＆＃39;或者＆＃39; +＆＃39;，这意味着它将返回bing.com/search for 2nd url和bing.com/efesdf for 3rd，删除任何＆＃39;？＆＃39;或者＆＃39; +＆＃39;

因此我尝试了以下代码

SELECT substring(url,1,instr(pattern,'?')-1) FROM testTable;

然而，在没有＆＃39;？＆＃39;将显示为＆＃34;＆＃34;，是否可以执行if语句，如

if (url.includes('?')){
SELECT substring(url,1,instr(url,'?')-1)
}
else if (url.includes('+')){
SELECT substring(url,1,instr(url,'+')-1)}
}  
else{
SELECT URL
}
FROM testTable;

如果我想选择*并仅更改网址，该怎么办？

请协助，感谢。

Answer 1

也许你需要这个;）

SELECT
    *,
    CASE WHEN LOCATE('?', url) THEN LEFT(url, LOCATE('?', url) - 1)
    WHEN LOCATE('+', url) THEN LEFT(url, LOCATE('+', url) -1)
    ELSE url END AS editedUrl
FROM testTable;

检查SQLFiddle DEMO HERE。

Answer 2

你需要这个？ Detail

select id, 
        (
        CASE 
            WHEN qty_1 <= '23' THEN price
            WHEN '23' > qty_1 && qty_2 <= '23' THEN price_2
            WHEN '23' > qty_2 && qty_3 <= '23' THEN price_3
            WHEN '23' > qty_3 THEN price_4
            ELSE 1
        END) AS total
     from product;

Answer 3

您可以尝试这样

SELECT CASE 
            WHEN LOCATE('?', url ) > 0 
               THEN SUBSTRING( url, 0, LOCATE('?', url ) -1 )
            WHEN LOCATE('+', url ) > 0
                THEN SUBSTRING( url, 0, LOCATE('?', url ) -1 )
               ELSE url 
       END as url
FROM testTable;

如何在Mysql中选择if if语句

3 个答案: