在单个查询中将结果作为单个数组获取

Question

I need to join tables and fetch output as single array in single query, even though a user has multiple address

My query:

SELECT user.name, address.address, user.place 
FROM user 
LEFT JOIN address 
WHERE user.user_id = address.user_id 
GROUP BY user.name, address.address, user.place

Suppose a user has multiple address am currently getting output as two rows.Is there any way to collect all output values in a single array using single query.

Please help.

Answer 1

You can use group_concat in your query.

SELECT user.name, group_concat(address.address) as 'address', user.place 
FROM user 
LEFT JOIN address 
WHERE user.user_id = address.user_id

Answer 2

Another way is to use FOR XML statement:

SELECT DISTINCT 
            u.name, 
            STUFF((SELECT ';' + a.[address]
            FROM address a
            WHERE u.[user_id] = a.[user_id]
            FOR XML PATH('')),1,1,'') as [address],
            u.place
FROM [user] u

Output will be like:

name    address         place
Mike    adr1;adr2;adr3  someplace

Answer 3

Try FOR XML PATH('') , it will join you addresses in one row:

select
    [user].[name],
    (select [address] + ', '
    from [address]
    where
        [user_id] = [user].[user_id]
    for xml path('')),
    user.place
from [user]