通过id列来聚合belong_user_saved列，应用string_agg函数，只要id一样则把第二列通过逗号连接起来
聚合前：
聚合后：
SELECT
C.ID,
string_agg(u.name::varchar,',') belong_user_saved
FROM
customer C
left join customer_territory ct on ct.customer = c.id
left join user_territory ut on ct.territory = ut.territory
left join user_info u on ut.user_info = u.id
WHERE
C.is_deleted = FALSE
and ct.is_deleted = false
and ut.is_deleted = false
and u.is_deleted = false
and u.enable = true
AND C.is_active = TRUE
AND C.record_type IN (
'hco',
'pharmacy',
'distributor')
group by C.ID
进阶版，通过having语句摘出来所有出现过两次以上的
SELECT
C.ID,
string_agg(u.name::varchar,','),
count(C.ID) as cnt
FROM
customer C
left join customer_territory ct on ct.customer = c.id
left join user_territory ut on ct.territory = ut.territory
left join user_info u on ut.user_info = u.id
WHERE
C.is_deleted = FALSE
and ct.is_deleted = false
and ut.is_deleted = false
and u.is_deleted = false
and u.enable = true
AND C.is_active = TRUE
AND C.record_type IN (
'hco',
'pharmacy',
'distributor')
group by C.ID
HAVING count(C.ID)>=2