I want to get some statitics out for my adminpanel.
I have two tables named users and cms_prosjekt. I want to count how many projects
that have the same attribute as users.
Each user have a motto that is connected to a project.
For example: Motto is spirit and the project code is spirit. It won't return anything. I have two users with the same motto as code in a project.
<?php
$result = mysql_query("SELECT
users.id,
COUNT(users.motto) AS count
FROM
users
LEFT JOIN cms_prosjekt ON
users.motto=cms_prosjekt.code
GROUP BY
users.motto");
$num_rows = mysql_num_rows($result);
echo "$num_rows";
?>
The query should be count(*) and group by user.motto
"SELECT
user.motto
, COUNT( * ) AS count
FROM users
LEFT JOIN cms_prosjekt ON users.motto=cms_prosjekt.code
GROUP BY users.motto"
The group by should be users.id not users.motto :
<?php
$result = mysql_query("SELECT users.id, COUNT(users.motto) AS count FROM users LEFT JOIN cms_prosjekt ON users.motto=cms_prosjekt.code GROUP BY (users.id)");
$num_rows = mysql_num_rows($result);
echo $num_rows;
?>
Note : i can't see any value for the left join you don't need any data from cms_prosjek but i keep it if you will use it later
I found the solution, but now I want to add a specific user id to the query. Since every administrator have their own home area, I want to list all the users that is connected to a specific administrator. Each administrator is creating projects with users.
I tried this:
$result = mysql_query("SELECT users.motto, COUNT( * ) AS count FROM users
WHERE id = '".$_SESSION['user']['id']."'
LEFT JOIN cms_prosjekt ON users.motto=cms_prosjekt.code
GROUP BY users.motto");
Related
I develop a chat system where students and staff can exchange different messages. I have developed a database where we have five tables: the staff table, the student, the message and two mapping tables the staff_message and stu_message. These tables contain only the student/staff id and the message id.
My problem is that I cannot order the messages. I mean that I cannot figure out how can I make one SQL statement that will return all messages and be ordered by for example the ID. The code that I have made is this:
$qu = mysqli_query($con,"SELECT * FROM stu_message");
while($row7 = mysqli_fetch_assoc($qu)){
$que = mysqli_query($con, "SELECT * FROM student WHERE studentid =".$row7['stu_id']);
while($row8 = mysqli_fetch_assoc($que)) {
$username = $row8['username'];
}
$query3 = mysqli_query($con, "SELECT * FROM message WHERE id=".$row7['mid']);
while($row6 = mysqli_fetch_assoc($query3)) {
echo $row6['date']."<strong> ".$username."</strong> ".$row6['text']."<br>";
}
}
$query2 = mysqli_query($con, "SELECT * FROM staff_message");
while($row3 = mysqli_fetch_assoc($query2)){
$query = mysqli_query($con, "SELECT * FROM staff WHERE id =".$row3['staff_id']);
while($row5 = mysqli_fetch_assoc($query)) {
$username = $row5['username'];
}
$query3 = mysqli_query($con, "SELECT * FROM message WHERE id=".$row3['m_id']);
while($row6 = mysqli_fetch_assoc($query3)) {
echo $row6['date']."<strong> ".$username."</strong> ".$row6['text']."<br>";
}
}
?>
The result is different from that I want. To be more specific first are shown the messages from the students and then from the staff. My question is, is there any query that it can combine basically all these four tables in one and all messages will be shown in correct order? for example by the id?
Thank you in advance!
First, use JOIN to get the username corresponding to the stu_id or staff_id, and the text of the message, rather than separate queries.
Then use UNION to combine both queries into a single query, which you can then order with ORDER BY.
SELECT u.id, u.text, u.username
FROM (
SELECT s.username, m.text, m.id
FROM message AS m
JOIN stu_message AS sm ON m.id = sm.mid
JOIN student AS s ON s.id = sm.stu_id
UNION ALL
SELECT s.username, m.text, m.id
FROM message AS m
JOIN staff_message AS sm ON m.id = sm.m_id
JOIN staff AS s ON s.id = sm.staff_id
) AS u
ORDER BY u.id
I need help at getting data from MySQL Database. Right now I have a query that gives me:
Tournament ID
Tournament Name
Tournament Entry fee
Tournament Start and End date
For tournaments I am registered in. Now I want, for each tournament I am registered in, to count how many users are in that tournament, my points in that tournament, etc.
That info is in table called 'ladder'
ladder.id
ladder.points
ladder.userFK
ladder.tournamentFK
Database: http://prntscr.com/99fju1
PHP CODE for displaying tournaments I am registered in:
<?php
include('config.php');
$sql = "SELECT distinct tournaments.idtournament, tournaments.name, tournaments.entryfee, tournaments.start, tournaments.end
from tournaments join ladder
on tournaments.idtournament= ladder.tournamentFK and ladder.userFK=".$_SESSION['userid']."
group by tournaments.idtournament";
$result = $conn->query($sql);
if($result->num_rows > 0){
while($row = $result->fetch_assoc()) {
$tournament="<li class='registered' data-id=".$row['idtournament']." data-entryfee=".$row['entryfee']." data-prize=".$tournamentPrize."><span class='name'>".$row['name']."</span><span class='entry-fee'>Entry fee: ".$row['entryfee']."€</span><span class='prize-pool'>Prize pool: €</span><span class='date-end'>".$row['start']."-".$row['end']."</span><span class='btns'><button>Standings</button></span></li>";
echo $tournament;
}
}
$conn->close();
?>
Usually you can combine JOIN, COUNT() and GROUP BY in your query.
Some examples:
MySQL joins and COUNT(*) from another table
This would be the query I think.Change column and table name if its not correct. Not tested but I am sure this will give you some idea to make required query
select count(ladder.tournamentId)as userCount,tournaments.name
from
ladder left join tournaments
on ladder.tournamentId = tournaments.id
where ladder.tournamentId in
(
select tournaments.id from
tournaments left join ladder
on ladder.tournamentId = tournaments.id
where ladder.userId='yourId'
) and ladder.userId <> 'yourId'
group by ladder.tournamentId
I first search all questions info. from "question" table including title, content, user etc.
the Code:
$sql = "select * FROM question where id>0 ORDER BY id ASC";
$result1 = mysql_query($sql);
$res=Array();
And then I want to search the user's point from "user" table. So I must search point for each user in each row from the result1
The Code:
while($rows=mysql_fetch_assoc($result1))
{
$res[]=$rows;
$user = $rows['user'];
$sql2 = "select point from user where name='$user'";
$result2 = mysql_query($sql2);
}
My problem is how to combine all the users' point(result2) with the questions info.(result1) together so that I can return a json for each row.
Use left join, as my understanding this work for you
$sql = "SELECT q.*, u.point AS point FROM question AS q LEFT JOIN user AS u ON q.user = u.name WHERE q.id > 0 ORDER BY q.id ASC";
$result = mysql_query($sql);
It's better go with the joins here i am giving you the query.i hope it may helps you
select * from question q,user u where q.id>0 ORDER BY id ASC
try something like this:using left join
select question.*,user.point FROM question left join user on user.name= question.name where id>0 ORDER BY id ASC
$sql = "SELECT * FROM books LEFT JOIN users
ON books.readby=users.user_id WHERE users.email IS NOT NULL";
$result = mysql_query($sql);
while($row = mysql_fetch_array($result))
{
echo $row['readby']. " - read 10 books";
} //while ends
this is the code I have so far. I am trying to retrieve the number of books read by each user
and echo the results. echo the user_id and number of books he/she read
books table is like this : id - name - pages - readby
the row readby contains the user id.any ideas/suggestions? I was thinking about using count() but Im not sure how to go about doing that.
A subquery can return the count of books read per user. That is left-joined back against the main table to retrieve the other columns about each user.
Edit The GROUP BY had been omitted...
SELECT
users.*,
usersread.numread
FROM
users
/* join all user details against count of books read */
LEFT JOIN (
/* Retrieve user_id (via readby) and count from the books table */
SELECT
readby,
COUNT(*) AS numread
FROM books
GROUP BY readby
) usersread ON users.user_id = usersread.readby
In your PHP then, you can retrieve $row['numread'] after fetching the result.
// Assuming you already executed the query above and checked errors...
while($row = mysql_fetch_array($result))
{
// don't know the contents of your users table, but assuming there's a
// users.name column I used 'name' here...
echo "{$row['name']} read {$row['numread']} books.";
}
You can use count() this way:
<?php
$count = mysql_fetch_array(mysql_query("SELECT COUNT(`user_id`) FROM books LEFT JOIN users ON books.readby=users.user_id WHERE users.email IS NOT NULL GROUP BY `user_id`"));
$count = $count[0];
?>
Hope this helps! :)
I have a query that retrieves the name of each friend a user has by joining that of friends and users tables. I have another table that stores active users. I need to retrieve friends that are active and not active but for some reason I am drawing a blank. If I have a list of all friends and a list of active friends, can I subtract active from all to be left with offline? All I Want to do basically is have two tabs. Under one will be offline friends. Under the other will be online friends. If anyone has any useful suggestions, I would appreciate it.
$sql = 'SELECT * FROM users
LEFT JOIN friendships
ON friendships.friend_id = users.id
WHERE friendships.user_id = ?';
$stmt5 = $conn->prepare($sql);
$result=$stmt5->execute(array($userid));
$count=$stmt5->rowCount();
//user has more than 0 friends
if ($count>0){
while ($row = $stmt5->fetch(PDO::FETCH_ASSOC)) {
$online=htmlspecialchars( $row['username'], ENT_NOQUOTES, 'UTF-8' );
//check whos online
$sql = 'SELECT * FROM active_users
WHERE username=?';
$stmt7 = $conn->prepare($sql);
$result=$stmt7->execute(array($online));
$count=$stmt7->rowCount();
while ($row = $stmt7->fetch(PDO::FETCH_ASSOC)) {
$activeuser=$row['username'];
}
}
This code just retrieves active users but hopefully gives an idea of structure.
Could you do a "not in" clause? Without knowing the layout of your database, I'm thinking something like this:
SELECT * FROM users
LEFT JOIN friendships
ON friendships.friend_id = users.id
WHERE friendships.user_id = ?
AND users.id NOT IN (
SELECT user_id FROM active_users
)
Using SQL to do this 'not in' is probably the best solution.
You could also do this in code if you really want to if the results are ordered. Just loop through the all users list, grab the first result from the active users list, and whenever there's a match, put that on the active users list and grab the next active user. Put every non-match into the inactive users list and only fetch from the all users list.
Something like this might tell you both lists in one shot:
SELECT users.username, active_users.username AS active FROM users
LEFT JOIN friendships
ON friendships.friend_id = users.id
LEFT JOIN active_users ON users.username = active_users.username
WHERE friendships.user_id = ?
Inactive users would return NULL in the active columns, where active would not.