Mysql select语句

Question

我需要一种合适的方式来写一个简单的WHERE，AND，OR语句。这个不起作用：

SELECT `content` 
  FROM `bx_wall_events` 
 WHERE `type` = 'wall_common_text' 
    OR `type` = 'wall_common_fb' 
    OR `type`= 'wall_common_tw' 
   AND `owner_id`='{$iId}' 
ORDER BY `date` DESC 
   LIMIT 1

Answer 1

这是一个有效的声明，但我认为问题是OR并没有像你预期的那样被解释。请改用IN语法：

  SELECT content
    FROM bx_wall_events
   WHERE `type` IN ('wall_common_text', 'wall_common_fb', 'wall_common_tw')
     AND `owner_id` = '{$iId}' 
ORDER BY `date` DESC 
   LIMIT 1

我删除了某些位置上的反标记，因为它们只在转义使用MySQL reserved keywords的表名和列名时才是必需的。

这样做的方式：

WHERE `type` = 'wall_common_text' 
   OR `type` = 'wall_common_fb' 
   OR `type`= 'wall_common_tw' 
  AND `owner_id`='{$iId}' 

...is评估为：

WHERE (`type` = 'wall_common_text')
   OR (`type` = 'wall_common_fb')
   OR (`type`= 'wall_common_tw' AND `owner_id`='{$iId}')

Answer 2

"SELECT content FROM bx_wall_events WHERE ((type= 'wall_common_text') || (type= 'wall_common_fb') || (type= 'wall_common_tw')) AND owner_id='{$iId}‘ORDER BY date DESC LIMIT 1“

Answer 3

使用IN找到了一个很好的解决方案

"SELECT `content` 
FROM `bx_wall_events` 
WHERE `owner_id`='{$iId}' 
AND `type`
IN ('wall_common_text', 'wall_common_fb', 'wall_common_tw') 
ORDER BY `date` 
DESC LIMIT 1"