How to fetch those records who appears in many records in many to many relationship in PostgreSQL?
I have the following three tables:
create table users(id int primary key, name varchar);
create table groups(id int primary key, name varchar);
create table user_groups(uid int references users(id), gid int references groups(id));
Following are the records in the respective tables:
insert into users values (1, 'John'), (2, 'Bob'), (3, 'Maria'), (4, 'Jin');
insert into groups values (1, 'Persons - A'), (2, 'Persons - B'),
(3, 'Persons - C'), (4, 'Persons - D'), (5, 'Pay - A'), (6, 'Pay - B'), (7, 'Pay - C');
insert into user_groups values (1, 1), (1, 2), (2, 1), (2, 4), (2, 6), (2, 7),
(3, 1), (3, 7), (4, 1), (4, 3);
Note: There are two types of groups, Persons and Pay
Now I want to find those users who have access to both types of groups (Persons and Pay), below is the desired output:
id name groups_user_has_access_to
2 Bob Persons - A, Persons - D, Pay - B, Pay - C
3 Maria Persons - A, Pay - C
The result should have only those users with their groups that have access to both types of groups.
Sorry for the bad English and appreciate your help in advance.
postgresql many-to-many
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
add a comment |
I have the following three tables:
create table users(id int primary key, name varchar);
create table groups(id int primary key, name varchar);
create table user_groups(uid int references users(id), gid int references groups(id));
Following are the records in the respective tables:
insert into users values (1, 'John'), (2, 'Bob'), (3, 'Maria'), (4, 'Jin');
insert into groups values (1, 'Persons - A'), (2, 'Persons - B'),
(3, 'Persons - C'), (4, 'Persons - D'), (5, 'Pay - A'), (6, 'Pay - B'), (7, 'Pay - C');
insert into user_groups values (1, 1), (1, 2), (2, 1), (2, 4), (2, 6), (2, 7),
(3, 1), (3, 7), (4, 1), (4, 3);
Note: There are two types of groups, Persons and Pay
Now I want to find those users who have access to both types of groups (Persons and Pay), below is the desired output:
id name groups_user_has_access_to
2 Bob Persons - A, Persons - D, Pay - B, Pay - C
3 Maria Persons - A, Pay - C
The result should have only those users with their groups that have access to both types of groups.
Sorry for the bad English and appreciate your help in advance.
postgresql many-to-many
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
add a comment |
I have the following three tables:
create table users(id int primary key, name varchar);
create table groups(id int primary key, name varchar);
create table user_groups(uid int references users(id), gid int references groups(id));
Following are the records in the respective tables:
insert into users values (1, 'John'), (2, 'Bob'), (3, 'Maria'), (4, 'Jin');
insert into groups values (1, 'Persons - A'), (2, 'Persons - B'),
(3, 'Persons - C'), (4, 'Persons - D'), (5, 'Pay - A'), (6, 'Pay - B'), (7, 'Pay - C');
insert into user_groups values (1, 1), (1, 2), (2, 1), (2, 4), (2, 6), (2, 7),
(3, 1), (3, 7), (4, 1), (4, 3);
Note: There are two types of groups, Persons and Pay
Now I want to find those users who have access to both types of groups (Persons and Pay), below is the desired output:
id name groups_user_has_access_to
2 Bob Persons - A, Persons - D, Pay - B, Pay - C
3 Maria Persons - A, Pay - C
The result should have only those users with their groups that have access to both types of groups.
Sorry for the bad English and appreciate your help in advance.
postgresql many-to-many
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
I have the following three tables:
create table users(id int primary key, name varchar);
create table groups(id int primary key, name varchar);
create table user_groups(uid int references users(id), gid int references groups(id));
Following are the records in the respective tables:
insert into users values (1, 'John'), (2, 'Bob'), (3, 'Maria'), (4, 'Jin');
insert into groups values (1, 'Persons - A'), (2, 'Persons - B'),
(3, 'Persons - C'), (4, 'Persons - D'), (5, 'Pay - A'), (6, 'Pay - B'), (7, 'Pay - C');
insert into user_groups values (1, 1), (1, 2), (2, 1), (2, 4), (2, 6), (2, 7),
(3, 1), (3, 7), (4, 1), (4, 3);
Note: There are two types of groups, Persons and Pay
Now I want to find those users who have access to both types of groups (Persons and Pay), below is the desired output:
id name groups_user_has_access_to
2 Bob Persons - A, Persons - D, Pay - B, Pay - C
3 Maria Persons - A, Pay - C
The result should have only those users with their groups that have access to both types of groups.
Sorry for the bad English and appreciate your help in advance.
postgresql many-to-many
postgresql many-to-many
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
edited 8 hours ago
Abdul Raheem Ghani
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
asked Jan 16 at 5:08
Abdul Raheem GhaniAbdul Raheem Ghani
158314
158314
add a comment |
add a comment |
1 Answer
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Here's my sample query for your question, the query could be slow depending on your table size
SELECT t.uid, u.name, t.groups_user_has_access_to
FROM (
-- Each of GID, finding its big group (PERSON, PAY) --> called: group_type.
-- Using distinct to remove duplicated element in group_type
SELECT ug.uid,
array_agg (distinct
case when g.name like 'Person%' then 'Person'
when g.name like 'Pay%' then 'Pay' end) as group_type,
array_agg(g.name) as groups_user_has_access_to
FROM user_groups ug
JOIN groups g on ug.gid = g.id
GROUP BY ug.uid
)t
JOIN users u on t.uid = u.id
WHERE array_length(t.group_type, 1) > 1 -- Reject any UID which belong to 1 group.
ORDER BY t.uid;
I would suggest you to read the array functions in the query above.
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
add a comment |
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1 Answer
1
active
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1 Answer
1
active
oldest
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active
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active
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Here's my sample query for your question, the query could be slow depending on your table size
SELECT t.uid, u.name, t.groups_user_has_access_to
FROM (
-- Each of GID, finding its big group (PERSON, PAY) --> called: group_type.
-- Using distinct to remove duplicated element in group_type
SELECT ug.uid,
array_agg (distinct
case when g.name like 'Person%' then 'Person'
when g.name like 'Pay%' then 'Pay' end) as group_type,
array_agg(g.name) as groups_user_has_access_to
FROM user_groups ug
JOIN groups g on ug.gid = g.id
GROUP BY ug.uid
)t
JOIN users u on t.uid = u.id
WHERE array_length(t.group_type, 1) > 1 -- Reject any UID which belong to 1 group.
ORDER BY t.uid;
I would suggest you to read the array functions in the query above.
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
add a comment |
Here's my sample query for your question, the query could be slow depending on your table size
SELECT t.uid, u.name, t.groups_user_has_access_to
FROM (
-- Each of GID, finding its big group (PERSON, PAY) --> called: group_type.
-- Using distinct to remove duplicated element in group_type
SELECT ug.uid,
array_agg (distinct
case when g.name like 'Person%' then 'Person'
when g.name like 'Pay%' then 'Pay' end) as group_type,
array_agg(g.name) as groups_user_has_access_to
FROM user_groups ug
JOIN groups g on ug.gid = g.id
GROUP BY ug.uid
)t
JOIN users u on t.uid = u.id
WHERE array_length(t.group_type, 1) > 1 -- Reject any UID which belong to 1 group.
ORDER BY t.uid;
I would suggest you to read the array functions in the query above.
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
add a comment |
Here's my sample query for your question, the query could be slow depending on your table size
SELECT t.uid, u.name, t.groups_user_has_access_to
FROM (
-- Each of GID, finding its big group (PERSON, PAY) --> called: group_type.
-- Using distinct to remove duplicated element in group_type
SELECT ug.uid,
array_agg (distinct
case when g.name like 'Person%' then 'Person'
when g.name like 'Pay%' then 'Pay' end) as group_type,
array_agg(g.name) as groups_user_has_access_to
FROM user_groups ug
JOIN groups g on ug.gid = g.id
GROUP BY ug.uid
)t
JOIN users u on t.uid = u.id
WHERE array_length(t.group_type, 1) > 1 -- Reject any UID which belong to 1 group.
ORDER BY t.uid;
I would suggest you to read the array functions in the query above.
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
Here's my sample query for your question, the query could be slow depending on your table size
SELECT t.uid, u.name, t.groups_user_has_access_to
FROM (
-- Each of GID, finding its big group (PERSON, PAY) --> called: group_type.
-- Using distinct to remove duplicated element in group_type
SELECT ug.uid,
array_agg (distinct
case when g.name like 'Person%' then 'Person'
when g.name like 'Pay%' then 'Pay' end) as group_type,
array_agg(g.name) as groups_user_has_access_to
FROM user_groups ug
JOIN groups g on ug.gid = g.id
GROUP BY ug.uid
)t
JOIN users u on t.uid = u.id
WHERE array_length(t.group_type, 1) > 1 -- Reject any UID which belong to 1 group.
ORDER BY t.uid;
I would suggest you to read the array functions in the query above.
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
edited Jan 16 at 9:05
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
answered Jan 16 at 9:00
Luan HuynhLuan Huynh
90611227
90611227
add a comment |
add a comment |
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