Question

我可以在里面做一个吗？或者只有在字段不为null（path = null）时才允许我进行检查的东西

SELECT  
IF(path IS NOT NULL, concat("/uploads/attachments/",path, "/thumbnails/" , nome), "/uploads/attachments/default/thumbnails/avatar.png") as avatar_mittente
FROM prof_foto  
WHERE profilo_id = 15 
 -- only if path != "/uploads/attachments/default/thumbnails/avatar.png"
AND foto_eliminata = 0 AND foto_profilo = 1

Answer 1

你可以试试这个

SELECT  
IF(path IS NOT NULL, concat("/uploads/attachments/",path, "/thumbnails/" , nome), "/uploads/attachments/default/thumbnails/avatar.png") as avatar_mittente
FROM prof_foto  
WHERE profilo_id = 15 
AND IF( path != "/uploads/attachments/default/thumbnails/avatar.png", 
         foto_eliminata = 0 AND foto_profilo = 1,
        foto_eliminata like '%' AND foto_profilo like '%'
        )

Answer 2

您可以使用二进制逻辑：

SELECT * FROM TABLE WHERE A
(if b then also where C)

变为

SELECT * FROM TABLE WHERE A 
AND (!b OR C)

在你的情况下：

SELECT  
IF(path IS NOT NULL, concat("/uploads/attachments/",path, "/thumbnails/" , nome), "/uploads/attachments/default/thumbnails/avatar.png") as avatar_mittente
FROM prof_foto  
WHERE profilo_id = 15 
AND (path = "/uploads/attachments/default/thumbnails/avatar.png" OR foto_eliminata = 0 AND foto_profilo = 1))

Answer 3

是的，您可以在预期值的任何地方使用IF()，即使大部分时间它都不是最佳路线。

WHERE IF(path IS NULL, portfolio_id = 15, TRUE)

但更喜欢：

WHERE path IS NULL OR portfolio_id = 15

（请注意，您无法与NULL进行比较，[anything] = NULL始终为FALSE）

如果里面有mysql

3 个答案: