在我的查询中摆脱工会…两个相似的选择有一个不同的条件 - getting rid of union on my query ... two similar select with one different condition

getting rid of union on my query ... two similar select with one different condition

假设有一个社交网络，我想显示我的登录用户的群组/朋友/家庭成员的最新活动

我在registry表中有所有活动，每个活动有3个不同的级别

0 => every one can see it
1 => only friends or in case of group, members can see it
2 => only family members can see it

我也有2个数组包含登录用户friends_groups AND family

select * from registry where user_id in (implode(',' ,  $groups_friends_array) ) && level < 2 
union
select * from registry where user_id in (implode(',' ,  $family_array) ) && level < 3

有没有办法在不使用联合的情况下做到这一点?

您可以使用OR合并两个WHERE子句

SELECT...
FROM...
WHERE  (user_id in (implode(',' ,  $groups_friends_array)) AND level < 2) OR
       (user_id in (implode(',' ,  $family_array)) AND level < 3)

select * from registry 
where 
(
  user_id in (implode(',' ,  $groups_friends_array) ) and level < 2
)
or
(
  user_id in (implode(',' ,  $family_array) ) and level < 3
)