问题
I need to make a query that creates 3 columns that come from 2 tables which have the following relations:
TABLE 1 has Column ID that relates to TABLE 2 with column ID2
In TABLE 1 there is a column called user In TABLE 2 there is a column called names
There can be 1 unique user but there can be many names associated to that user.
If i do the following i get all data BUT the user column repeats itself for each name it has associated. What i want is for use to appear unique but the names columns appear with all the names associated to the user column but separated by commas, like the following:
select user,names from TABLE1 left join TABLE2 on TABLE1.id = TABLE2.id
This will show the users repeated everytime a name appears for that user. what i want is to appear like this:
USER - NAMES
cyrex - pedrox, rambo, zelda
homeboy - carmen, carlos, tom, sandra
jerry - seinfeld, christine
ninja - soloboy
etc....
回答1:
What you are looking for is the GROUP_CONCAT operator.
select user, GROUP_CONCAT(names SEPARATOR ',')
from TABLE1 left join TABLE2 on TABLE1.id = TABLE2.id
group by user
来源：https://stackoverflow.com/questions/4609753/mysql-join-with-multiple-values-in-one-column