My database looks something like this, in order of user, userteam (connection table) and team:
Usertable UserTeam Teamtable
+--------+------+ +--------+--------+ +--------+-------+
| userid | name | | userid | teamid | | teamid | name |
+--------+------+ +--------+--------+ +--------+-------+
| 1 | eric | | 1 | 1 | | 1 | awsm |
| 2 | john | | 1 | 2 | | 2 | doe |
| 3 | carl | | 2 | 1 | | 3 | empty |
+--------+------+ | 3 | 1 | +--------+-------+
+--------+--------+
How do I select all users that IS NOT in a team, and echo them out only once? I've tried doing it with the usertable, but then it will echo for instance, if I try and select all members not in team 3:
SELECT userid FROM userteam WHERE teamid!=3;
SELECT * FROM user WHERE userid='$previousSql';
1 eric
1 eric
2 john
3 carl
What I'd like instead is:
1 eric
2 john
3 carl
I'm making an add members function, and I'd very much not like everyone to show up more than once.. Any directions, help or guiding would be much appreciated.
add
GROUP BY name
to the query
This should do it:
SELECT u.userid, u.name FROM Usertable u
INNER JOIN UserTeam ut ON ut.userid = u.userid
INNER JOIN Teamtable tt ON tt.teamid = ut.teamid
WHERE tt.teamid != 3
GROUP BY u.userid, u.name;
SELECT userid, name FROM usertable
JOIN userteam ON userteam.userid = usertable.userid
JOIN teamtable on teamtable.teamid = userteam.teamid
WHERE teamtable.teamid = 3;
The SQL above should do the proper joins between all the tables and then will only list the userid/names of people who have a teamid of 3 in the teamtable
EDIT* Removed ! from WHERE clause.
Related
I have these tables...
GROUP_MEMBERS
+---------------------------------+
| id | group_id | member_id |
+---------------------------------+
| 1 | 1 | 1 |
| 2 | 1 | 4 |
+---------------------------------+
MEMBERS
+-------------------------------------+
| id | first | last | role_id |
+-------------------------------------+
| 1 | Jack | Jones | 1 |
| 2 | Jane | Doe | 2 |
| 3 | Bob | Bee | 2 |
| 4 | Jen | Nee | 1 |
+-------------------------------------+
GROUPS
+-----------------+
| id | name |
+-----------------+
| 1 | group1 |
| 2 | group2 |
+-----------------+
As it is, I am using the following query...
SELECT
(members.id) AS memid,
members.first,
members.last,
members.role_id
FROM
members
LEFT JOIN group_members ON
members.id = group_members.member_id
WHERE
group_members.member_id IS NULL
GROUP BY
members.id;
This outputs the members (Jane and Bob) who are not in the 'GROUP_MEMBERS' table as it should, but what I am trying get working is if I am on and another group ($_GET['group_id']), how can I show all members that do not have rows that match group_id and member_id on the 'GROUP_MEMBERS' table...
i.e if group_id = '2' show all members
I have tried adding in WHERE clause... AND group_members.group_id IS NULL.. but it shows nothing then.
Does anyone have a query which would get the output I'm looking for?
Thanks
[EDITED]
Just to clarify...
If my url had 'group_id=1'
I should see:
Bob
Jane
If my url has 'group_id=2'
I should see:
Jack
Jane
Bob
Jen
So it only shows 'members' that do not exist( with the 'group_id' in the url) in the 'GROUP_MEMBERS' table
If I have understood the question correctly, you are looking for something like I have made on this fiddle:
DB Fiddle
The query I use is:
$sql = 'SELECT * FROM groups
RIGHT JOIN group_members ON groups.id = group_id
RIGHT JOIN members ON member_id = members.id
WHERE group_id <> ? OR group_id is NULL;'
$group_id = $_GET['group_id'];
$query = $mysqli->prepare($sql);
$query->bind_param('i', $group_id);
In short, this query will select from the groups table, ensuring that we will select every group in your database.
Then we will join the other two tables completely (using the RIGHT JOIN).
Finally, we are going to select every member that isn't the specified the one provided by the URL, or any member that is not in a group.
You can use a sub-query
how can I show all members that do not have rows that match 'group_id'
$group_id= $_GET['group_id'];
$q = "SELECT * FROM MEMBERS WHERE MEMBERS.id NOT IN(
SELECT member_id FROM GROUP_MEMBERS WHERE group_id='$group_id'
);";
Explanation
SELECT member_id FROM GROUP_MEMBERS WHERE group_id='$grID'
this will get all the members in this group by a given ID
then you select all members that are not among them.
SELECT * FROM MEMBERS WHERE MEMBERS.id NOT IN()
this one will give members data except the ids inside the brackets
the sub query will get the ids of members in a given group
no need for joining the three tables since you are using id of the group existing in GROUP_MEMBERS and linking the GROUP and MEMBERS
one side note
if you have a group name and what all users not in this group you then will need to use the GROUPS table
SELECT * FROM MEMBERS WHERE MEMBERS.id NOT IN(
SELECT member_id FROM GROUP_MEMBERS WHERE group_id = (
SELECT id from GROUPS WHERE name = '$Group_Name'
)
);
you may use WHERE group_id IN (...) it will work the same
This is a demonstration, I created same database with same data and tested the queries
+----+-------+-------+---------+
| id | first | last | role_id |
+----+-------+-------+---------+
| 1 | Jack | Jones | 1 |
| 2 | Jane | Doe | 2 |
| 3 | Bob | Bee | 2 |
| 4 | Jen | Nee | 2 |
+----+-------+-------+---------+
+----+--------+
| id | name |
+----+--------+
| 1 | group1 |
| 2 | group2 |
+----+--------+
+----+----------+-----------+
| id | group_id | member_id |
+----+----------+-----------+
| 1 | 1 | 1 |
| 2 | 1 | 4 |
+----+----------+-----------+
I run the sub-query as above and the results as expected,
MariaDB []> select * from members where id not in
(select member_id from group_members where group_id = 1);
+----+-------+------+---------+
| id | first | last | role_id |
+----+-------+------+---------+
| 2 | Jane | Doe | 2 |
| 3 | Bob | Bee | 2 |
+----+-------+------+---------+
similar for when you have group name
MariaDB []> select * from members where id not in
(select member_id from group_members where group_id =
(select id from groups where name='group1'));
+----+-------+------+---------+
| id | first | last | role_id |
+----+-------+------+---------+
| 2 | Jane | Doe | 2 |
| 3 | Bob | Bee | 2 |
+----+-------+------+---------+
I have 2 table as below:
Table 1: common_member
+-----------+-----------+
| uid | username |
+-----------+-----------+
| 1 | haha |
| 2 | walao |
| 3 | alamak |
| 4 | hero |
| 5 | theone |
| 6 | nobody |
+-----------+-----------+
Table 2: labour_slog
+--------------+-------------+--------------+-------------+
| uid | slaveid | masterid | bytime |
+--------------+-------------+--------------+-------------+
| 1 | 2 | 3 | 123456 |
| 4 | 5 | 6 | 456789 |
+--------------+-------------+--------------+-------------+
I fetch the data as script below:
$queryLabourSlog = DB::query("SELECT * FROM ".DB::table('labour_slog')." ORDER BY id desc");
while($rowLabourSlog = DB::fetch($queryLabourSlog)) {
$user_list_slog[] = $rowLabourSlog;
};
array_multisort($idss, SORT_DESC, $user_list_slog);
In my html, I use
<!--{loop $user_list_slog $value}-->{$value[uid]} on {$value[bytime]} forced hire {$value[masterid]}'s employee {$value[slaveid]}.<!--{/loop}-->
The html will display:
1 on 123456 forced hire 3's employee 2.
4 on 456789 forced hire 6's employee 5.
How do I join the Table 1's username data to get the loop display as below?
haha on 123456 forced hire alamak's employee walao.
hero on 456789 forced hire nobody's employee theone.
Thanks.
SELECT table_slog.*, u1.`name`, u2.`name` FROM `table_slog` LEFT JOIN `common_member` AS u1 ON `table_slog`.`uid`=u1.`uid` LEFT JOIN `common_member` AS u2 ON `table_slog`.`slaveid`=u2.`uid` LEFT JOIN `common_member` AS u3 ON `table_slog`.`masterid`=u3.uid ORDER BY `id` DESC
Something like that:
SELECT `uid_main`.`username` AS `main_username`,
`uid_main`.`uid` AS `main_uid`,
`uid_master`.`username` AS `master_username`,
`uid_master`.`uid` AS `master_uid`,
`uid_slave`.`username` AS `slave_username`,
`uid_slave`.`uid` AS `slave_uid`,
`ls`.`bytime` AS `bytime`
FROM `labour_slog` AS `ls`
LEFT JOIN `common_member` AS `uid_main` ON (`ls`.`uid` = `cm`.uid)
LEFT JOIN `common_member` AS `uid_master` ON (`ls`.`master_id` = `cm`.uid)
LEFT JOIN `common_member` AS `uid_master` ON (`ls`.`slave_id` = `cm`.uid)
ORDER BY `cm`.`uid` DESC
I have 2 tables in database:
How can I get total user for each group. i.e: group 1: total are 2 users;
group2: total are 2 users;
group3: total is 1 user
You need normalization and never store comma-separated data.
Consider the following
mysql> select * from user_table ;
+---------+---------------+
| user_id | user_group_id |
+---------+---------------+
| 1 | 1,2 |
| 2 | 2 |
| 3 | 1,3 |
+---------+---------------+
3 rows in set (0.00 sec)
mysql> select * from group_table ;
+----------+------------+
| group_id | group_name |
+----------+------------+
| 1 | a |
| 2 | b |
| 3 | c |
+----------+------------+
3 rows in set (0.00 sec)
The above data is not normalized and to get the desired result out of these you need to use some in-efficient query as
select
g.group_id,
count(*) as total
from group_table g
left join user_table u on find_in_set(g.group_id,u.user_group_id) > 0
group by g.group_id ;
+----------+-------+
| group_id | total |
+----------+-------+
| 1 | 2 |
| 2 | 2 |
| 3 | 1 |
+----------+-------+
Now lets do normalization and store user-group data in a different table as
mysql> select * from user_to_group ;
+---------+----------+
| user_id | group_id |
+---------+----------+
| 1 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 1 |
| 3 | 3 |
+---------+----------+
You can easily write different queries from these tables now and here are some examples
select group_id,count(*) as tot from user_to_group group by group_id ;
+----------+-----+
| group_id | tot |
+----------+-----+
| 1 | 2 |
| 2 | 2 |
| 3 | 1 |
+----------+-----+
Joining the tables would even more easy
select
g.group_id,
g.group_name,
count(*) as tot
from user_to_group ug
join group_table g on g.group_id = ug.group_id
join user_table u on u.user_id = ug.user_id
group by g.group_id
+----------+------------+-----+
| group_id | group_name | tot |
+----------+------------+-----+
| 1 | a | 2 |
| 2 | b | 2 |
| 3 | c | 1 |
+----------+------------+-----+
SELECT group_name, COUNT(*) FROM user_table u, group_table g WHERE u.user_group_id LIKE %g.group_id% GROUP BY g.group_name;
this should work and give you a list of all groups and how many users are in them.
I will recommend you to create a third table which holds the information about which users are in which groups.
CREATE TABLE users_in_groups
(
user_id INT
, group_id INT
);
Then you can join like this:
SELECT
gt.group_id
, count(ut.user_id)
FROM
user_table AS ut
, INNER JOIN users_in_groups AS uig ON uig.user_id = ut.user_id
, INNER JOIN group_table AS gt ON gt.group_id = uig.group_id
GROUP BY
gt.group_id
;
To use the table you have now will you have to do something like this (in mysql):
SELECT
gt.group_id
, count(ut.user_id)
FROM
user_table AS ut
, INNER JOIN group_table AS gt ON LOCATE(gt.group_id, ut.user_group_id) > 0
GROUP BY
gt.group_id
Remember, when using group by, always locate what makes your group unique!
This is not an answer to your specific question but rather an alternative data structure proposal that might be better.
Introduce a new table members that looks like
# members
user_id | group_id
1 | 1
1 | 2
2 | 2
3 | 1
3 | 3
Then you could SELECT group_id, count(*) FROM members GROUP BY group_id
+----------+----------+
| group_id | count(*) |
+----------+----------+
| 1 | 2 |
| 2 | 2 |
| 3 | 1 |
+----------+----------+
This structure might also make it easier for you to manage your memberships. user_id + group_id should be unique. And if supported let them be foreign keys.
I will try to be as explanatory as possible regarding my question. I am using MYSQL/PHP to fetch data from two tables with the structure looking like the following:
table A
+---------+------------+
| userid | username |
+---------+------------+
| 1 | john |
| 2 | doe |
| 3 | lewis |
+---------+------------+
table B
+---------+------------+-----------+
| id |from_userid | to_userid |
+---------+------------+-----------+
| 1 | 1 | 3 |
| 2 | 3 | 2 |
| 3 | 1 | 2 |
| 4 | 2 | 1 |
+---------+------------+-----------+
Am trying to achieve the following:
+---------+------------+----------------------+
| id |sender username| receiver username |
+---------+------------+----------------------+
| 1 | john | lewis |
| 2 | lewis | doe |
| 3 | john | doe |
| 4 | doe | john |
+---------+------------+----------------------+
As you can see, instead of returning the sender or receiver user id, I am returning their username according to Table A.
can I use left or right joins in this scenario? Thanks in advance
Try this
SELECT b.id, sender.username AS sender_username, receiver.username AS receiver_username
FROM tableB AS b
JOIN tableA AS sender ON b.from_userid = sender.userid
JOIN tableA AS receiver ON b.to_userid = receiver.userid
Inner joins would work fine, you just need to do two of them...
Left and right joins are only needed when you want to get all records from one table and some from another table. In this case you have two distinct relationships thus the need for two joins. My MySQL skills are a bit rusty so I don't know if ' or [ are used as separators on the table/field names with spaces.
Select t1.ID, T1.userName as 'Sender userName', T2.username as 'Receiver username'
FROM [Table A] A
INNER JOIN [Table B] T1
on T1.from_userid = A.userID
INNER JOIN [Table B] T2
on T2.to_userid = A.userID
I have 2 tables in MySQL:
Persons
|ID | Name | Address
---------------------------------
| 1 | Someone | Somewhere
| 2 | Person2 | Somewhere else
And the table ActivePages
|ID | PersonID | Page
---------------------------------------
| 1 | 1 | somepage
| 1 | 1 | someotherpage
Now I need a query to return the following:
|PersonID | Count
------------------
|1 | 2
|2 | 0
------------------
Who can help me with this? I think its straight forward but I keep getting wrong values...
Thanks in advance!
SELECT p.ID AS PersonID,
COUNT(a.PersonID) AS `Count`
FROM Persons p
LEFT JOIN ActivePages a ON a.PersonID = p.ID
GROUP BY p.ID
select personid,count(personid) as count from activepages
right join Persons on ActivePages.PersonID = Persons.ID group by personid