两个表的SQL查询

Question

I will try to explain the problem I'm facing.

I have two tables: Team and Team_contacts

In the first table there is info like: member_name, member_picture, phone and email

In the team_contacts table there are only countries and cities the member is responsible for.

So the first table looks like this:

member_id: 1
member_name: moonwalker
member_picture: mw.jpg
member_phone: 06xxxxxxxx
member_email: mw@moonwalker.com

The second table looks like this:

member_id: 1
country: USA
city: California

member_id: 1
country: USA
city: Miami

member_id: 1
country: NL
city: Amsterdam

What I need is a query that shows the following:

mw.jpg 
Moonwalker 
Phone: 06xxxxxxxx 
Email: mw@moonwalker.com 
Active in countries: USA, NL 
Active in cities: California, Miami, Amsterdam

I tried different join methods, but nothing seems to work. Is there a way to do this with a single query or do I need to use two different queries? And how?

Thanks a lot for the help.

Answer 1

As you are using MySQL you can do:

SELECT team.*,
       GROUP_CONCAT(team_contacts.country SEPARATOR ", ") AS active_in_countries,
       GROUP_CONCAT(team_contacts.city SEPARATOR ", ") AS active_in_cities
FROM team
JOIN team_contacts USING (team_id)
GROUP BY team.member_id

Be aware that the length of the list is limited by group_concat_max_len which is by default 1024, unless you change it using for example:

SET SESSION group_concat_max_len = @@max_allowed_packet