Question

我有一个“deal”表，其中包含“id”，“name”，“created_at”......列。我有一个“speciallisting_deal”数据透视表，它保持特殊列表和交易之间的关系。它的列是“id”，“deal_id”，“speciallisting_id”......

在我的情况下，speciallisting_id是肯定的，比方说10.根据某些标准（如created_at等排序）从“deal”表中获取结果，我想优先考虑（我的意思是我想看到它们）在结果的顶部）到“交易”中的行，其中的ID是“（SELECT deal_id FROM speciallisting_deal WHERE speciallisting_id = 10）”或等价物。

我该怎么做？

Answer 1

您可以在case中使用order by语句：

order by (case when specialist_id = 10 then 0 else 1 end),
         created_at desc

Answer 2

简单的左连接可能就足够了。提供你自己尝试做的事情真的更好。

SELECT

    d.id,
    d.name,
    d.created_at,
    -- Find out if this is considered "special"
    IF(sd.id IS NULL,0,1) AS isSpecial

FROM deals d

-- Left join the speciallistings onto this
LEFT JOIN speciallisting_deal sd
    ON sd.deal_id = d.id
    -- You don't have to specify a specific ID if you just want to get all that are special
    AND sd.speciallisting_id = 10
    -- You could do multiple speciallisting_id's using IN
    -- AND sd.speciallisting_id IN (8,2,10,314)

ORDER BY 
    isSpecial DESC, 
    d.created_at DESC

在订购时优先考虑mysql中的某些行

2 个答案: