I having two tables
table 1: users
| id | username |
| 1 | john |
| 2 | marry |
| 3 | deep |
| 4 | query |
| 5 | value|
and
table 2:users_2
| table_2_id | user_id |
| 1 | 2,4 |
I need required something like this
| table_2_id | username |
| 1 | marry,query |
anyone can help me for this output in mysql
Is this what you are looking ?
select
`users_2`.`table_2_id` , GROUP_CONCAT(`users`.`username`) as `usernames`
from `users_2`
inner join `users` on FIND_IN_SET(`users`.`id`,`users_2`.`user_id`)
Check output here
http://sqlfiddle.com/#!2/c498bc/3
select a.table_2_id,b.username
from users b,users_2 a
where a.table_2_id=b.id
and b.id in(a.user_id)
group by a.table_2_id
First of all, you should not store a multiple value in a single field. For table users_2, the data should be:
table_2_id user_id
1 2
1 4
After you normalized your table, you can use mysql GROUP_CONCAT() to get the result in the format you mentioned
SELECT
users_2.table_2_id,
GROUP_CONCAT(users.username) AS username
FROM
users_2
JOIN
users ON users.id = users_2.user_id
GROUP BY
users_2.table_2_id
;
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 |
+----+-------+------+---------+
unfortunately i have to do this in mysql / php . I looked for three days, and there is like 10.000 explantions of this but NONE (and I repeat NONE) works for me. I tried it all. I have to ask, sorry.
I have two tables - articles and control.
table "articles"
------------------
art_id | name |
------------------
1 | aaa |
2 | bbb |
3 | ccc |
4 | ddd |
table "control"
--------------------------------------------
con_id | art_id | data |
--------------------------------------------
1 | 1 | something-a |
2 | 2 | something-b |
3 | 1 | something-a |
4 | 2 | something-c |
5 | 3 | something-f |
art_id exists in both tables. Now what i wanted - for query:
"select * from articles order by art_id ASC" displayed in a table
to have also one cell displaying the count for each of art_id's from table CONTROL...
and so i tried join, left join, inner join - i get errors ... I also tried for each get only one result (for example 2 for everything)... this is semi-right but it displays the array of correct results and it's not even with join!!! :
$query = "SELECT art_id, count(*) as counting
FROM control GROUP BY art_id ORDER BY con_id ASC";
$result = mysql_query($query);
while($row=mysql_fetch_array($result)) {
echo $row['counting'];
}
this displays 221 -
-------------------------------------------------
art_id | name | count (this one from control) |
-------------------------------------------------
1 | aaa | 221 |
2 | bbb | 221 |
3 | ccc | 221 |
and it should be:
for art_id(value1)=2,
for art_id(2)=2,
for art_id(3)=1
it should be simple - like a count of values from CONTROL table displayed in query regarding the "articles" table...
The result query on page for table articles should be:
"select * from articles order by art_id ASC"
-------------------------------------------------
art_id | name | count (this one from control) |
-------------------------------------------------
1 | aaa | 2 |
2 | bbb | 2 |
3 | ccc | 1 |
So maybe i should go with JOIN or with join plus for each... Tried tha too, but then i'm not sure what is the proper thing to echo... all-in-all i'm completely lost here. Please help. Thank you.
So imagine this in two steps:
Get the counts per art_id from the control table
Using your articles table, pick up the counts from step 1
That will give you a query that looks like this:
SELECT a.art_id, a.name, b.control_count
FROM articles a
INNER JOIN
(
SELECT art_id, COUNT(*) AS control_count
FROM control
GROUP BY art_id
) b
ON a.art_id = b.art_id;
Which will give you the results you're looking for.
However, instead of using a subquery, you can do it all in one shot:
SELECT a.art_id, a.name, COUNT(b.art_id) AS control_count
FROM articles a
INNER JOIN control b
ON a.art_id = b.art_id
GROUP BY a.art_id, a.name;
SQL Fiddle demo
SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id DESC;
If I understood your question right, this query should do the trick.
Edit: Created the tables you have described, and it works.
SELECT * FROM articles;
+--------+------+
| art_id | name |
+--------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
| 4 | ddd |
+--------+------+
4 rows in set (0.00 sec)
SELECT * FROM control;
+--------+--------+------+
| con_id | art_id | data |
+--------+--------+------+
| 1 | 1 | NULL |
| 2 | 2 | NULL |
| 3 | 1 | NULL |
| 4 | 2 | NULL |
| 5 | 3 | NULL |
+--------+--------+------+
5 rows in set (0.00 sec)
SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id ASC;
+--------+------+----------------+
| art_id | name | count_from_con |
+--------+------+----------------+
| 1 | aaa | 2 |
| 2 | bbb | 2 |
| 3 | ccc | 1 |
| 4 | ddd | 0 |
+--------+------+----------------+
You haven't quite explained what you want to accomplish with the print out but here is an example in PHP: (Use PDO instead of mysql_)
$pdo = new PDO(); // Make your connection here
$stm = $pdo->query('SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id ASC');
while( $row = $stm->fetch(PDO::FETCH_ASSOC) )
{
echo "Article with id: ".$row['art_id']. " has " .$row['count_from_con'].' connected rows in control.';
}
Alternatively with the mysql_ extension:
$result = mysql_query('SELECT *, (SELECT COUNT(control.con_id) FROM control WHERE control.art_id = articles.art_id) AS count_from_con FROM articles ORDER BY art_id ASC');
while( $row = mysql_fetch_assoc($result) )
{
echo "Article with id: ".$row['art_id']. " has " .$row['count_from_con'].' connected rows in control.';
}
This should be enough examples to help you accomplish what you need.
In my messages table I have following rows for example,
|----|---------|--------------|------|
| id | user_id | message |status|
|====|=========|==============|======|
| 1 | 2 | msgs 11 | r |
|----|---------|--------------|------|
| 2 | 3 | msgs 12 | r |
|----|---------|--------------|------|
| 3 | 2 | msgs 13 | r |
|----|---------|--------------|------|
| 4 | 3 | msgs 14 | u |
|----|---------|--------------|------|
Now, I need to know two things for each user_id
Whether it has any status u or not.
How many messages are there
For example, a query like below
select user_id, status, count(*) as totalMsg from messages group by user_id
Would brought me following rows
| user_id | status| totalMsg |
|=========|=======|==========|
| 2 | r | 2 |
|---------|-------|----------|
| 3 | r | 2 |
^
|------> I need this value to be 'u' because user 3 has a message u
My current query doesnt really gurantee that it will look for a u in the status column.
Is that possible to do? If so how?
MAX() will work on this since r is the least value based on the lexicographical order.
SELECT user_ID,
MAX(status) status,
COUNT(*) totalMsg
FROM messages
GROUP BY user_ID
I want my users to be able to make a favourite list.
I have two tables in a database in mySQL. One stores information about businesses and the other stores the unique user ids as well as the ids from the first table that the user has marked a favourite.
Table 1
<pre>
ID | NAME | EMAIL | PHONE |
1 | Joe | a#mail.com | 25634565 |
2 | John | b#mail.com | 43634565 |
3 | Jack | c#mail.com | 65634565 |
4 | James| d#mail.com | 43634565 |
5 | Julie| e#mail.com | 65634565 |
...
</pre>
Table 2
<pre>
USERID | FAV1 | FAV2 | FAV3 | FAV...
2565325489 | 1 | 3 | 5 |
8596854785 | 3 | 2 | NULL |
2356256263 | 5 | NULL | NULL |
...
</pre>
The output I want for a user (in this example the first in table2):
<pre>
Joe | a#mail.com | 25634565 |
Jack | c#mail.com | 65634565 |
Julie| e#mail.com | 65634565 |
</pre>
I have looked into JOIN LEFT and minus query calls, but I just can't make it work. I have a basic understanding of mySQL and PHP, but not a lot.
I would highly appreciate any help with what approach to take.
Ps. If there are better ways to structures my databases, I would love to know.
I'd use a table with two fields - userID and fav - make one entry for each entry. And then...
SELECT table1.name, table1.email, table1.phone FROM table1,table2 WHERE table2.fav = table1.id AND table2.userid = 2565325489
Select * from table1 InnerJoin (Select * from table2) as t4 on table1.ID=t4.FAV1
$result = mysqli_query('SELECT name,email,phone FROM t1 table1 LEFT JOIN table2 t2 ON t1.ID = t2.fav1');
//iterate the results
while ($row = mysqli_fetch_array($result))
{
echo $row['name']." ".$row['email']." "$row['phone'];
}
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