SQL查询与一对多关系的多个表联接

Question

I have following tables:

tbl_destination

id_destination INT PRIMARY
destination_name VARCHAR(200)

tbl_destination_category

id_destination_category INT PRIMARY
id_destination INT
id_category INT

tbl_destination_activity

id_destination_activity INT PRIMARY
id_destination INT
id_activity INT

tbl_category

id_category INT PRIMARY
category_name VARCHAR(200)

tbl_activity

id_activity INT PRIMARY
activity_name VARCHAR(200)

I want to select destination data, with category and activity WHERE:

• One destination can have many category (tbl_destination one-to-many tbl_destination_category)
• One destination can have many activity (tbl_destination one-to-many tbl_destination_activity)

My expected output example:

---------------------------------------------------------------------------------------------------------------------
Destination name Category Activity
---------------------------------------------------------------------------------------------------------------------
Mount Everest Mountain, nature Hiking, Trekking, Camping

Is this possible to do in one single query? or whats the most efficient query?

Answer 1

you would have more than one row per relationships, but your SQL is here:

 select td.destination_name,  tc.category_name, ta.activity_name
 from tbl_destination td
 inner join tbl_destination_category tdc on tdc.id_destination = td.id_destination 
    iiner join tbl_destination_activity tda on tda.id_destination = td.id_destination 
    iiner join tbl_category tc on tc.id_category = tdc.id_category 
    inner join tbl_activity ta on ta.id_activity  = tda.id_activity