I have to tables.
The first one (members) contains my customers
id|name|email|key
The second (types) contains listings customer subscribes to
id|customer_id|type|active
What I would like to do is to list all members that subscribed to a type of list.
I can do this with 2 sql:s, but I guess there must be a better and faster way using som kind if JOIN maby and besides I get the wrong ORDER for my customers doing my way. I want ORDER by name.
<?
$type ='555';
$sql = mysql_query(" SELECT * FROM types WHERE type='$type' && active='1' ");
while($a = mysql_fetch_array($sql))
{
$sql2 = mysql_query(" SELECT * FROM members WHERE id='{$a['customer_id']}' ");
while($b = mysql_fetch_array($sql2))
{
echo 'Name: '.$b['name'].'<br>';
}
}
?>
mysql_query(" SELECT * FROM types INNER JOIN members ON types.customer_id = members.id WHERE type='$type' AND active='1' ORDER by members.name ASC");
This should do the trick for you
SELECT * FROM members
JOIN types ON members.id = types.customer_id
WHERE types.type = ? AND types.active = '1'
ORDER BY members.name
perhaps this:
SELECT m.name, m.email
FROM members m left join types t
ON m.id=t.customer_id
WHERE t.type='$type' and t.active='1';
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 have a simple blog where I'm practicing some php and mysql. I'm trying to display the username of the post author (you know where it says posted by Author).
I have two tables blog_members and blog_posts which are related 1 to many so I got a memberID field into the blog_posts. I'm trying to get the username of the member who's the author of the post.
I was thinking to do a join or something but I can't figure this out.
Here's what I was trying to do but it's not working because I'm sure I'm not using it properly.
$query1 = "SELECT username from blog_members JOIN blog_posts ON memberID = memberID ";
$result1 = mysqli_query($link, $query1);
$row1 = mysqli_fetch_array($result1);
PS: I got it working one way by using SESSION to get the userID but that works only if the user is logged is which is not the case, I want to display the name in any case.
Thanks!
Use inner join this way
And with a proper sanitize use $your_user_id for match
$query1 = "SELECT username
from blog_members
INNER JOIN blog_posts ON blog_members.memberID = blog_posts.memberID
WHERE blog_posts.memberID = '" .$your_user_id . "';";
JOIN syntax is wrong in your query.
Use following query:
$query1 = "SELECT username from blog_members JOIN blog_posts ON blog_members.memberID = blog_posts.memberID ";
$result1 = mysqli_query($link, $query1);
$row1 = mysqli_fetch_array($result1);
Try something like this, usng INNER JOIN :
$query1 = "SELECT blog_members.username FROM blog_members INNER JOIN blog_posts ON blog_members.memberID = blog_posts.memberID ";
reference : http://www.w3schools.com/sql/sql_join.asp
Here is a solution using a simple WHERE condition (same performance Explicit vs implicit SQL joins) :
SELECT a.username FROM blog_members a, blog_posts b WHERE a.memberID = b.memberID
But if you need more information about MySQL Join : https://www.sitepoint.com/understanding-sql-joins-mysql-database/
Hope this helps !
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
i am joining the two tables but is giving me error that mysql_fetch_array() expects parameter 1 to be resource,
<?php
$result=mysql_query("SELECT * FROM `photo_gallery`.`photographs` WHERE id=1");
$result .=mysql_query("SELECT * FROM `photo_gallery`.`users` WHERE id=1");
while($row=mysql_fetch_array($result))
{
echo 'You are Welcome'.'<br/>';
$Id=$row['id'];
$Name=$row['username'];
$Batch=$row['password'];
$Address=$row['first_name'];
$Course=$row['last_name'];
$filename=$row['filename'];
$type=$row['type'];
echo 'your ID is'.$Id.'<br/>'.'username '. $Name.'<br/>'.'your password '. $Batch.'<br/>'.'yor first name'. $Address. '<br/>'.'last'.$Course.'<br/>'.'file name is'.'<br/>'.$filename.'<br/>'.'type is '.$type;
}
?>
Here is the most easy syntax to use join function
$query=mysql_query("SELECT * FROM `databasename`.`firstablename` JOIN `seconddatabasename` ON firsttablename.id = secondtablename.id ");
If you want to work with join array than visit this link http://www.w3schools.com/php/func_string_join.asp.
I hope you get what join function is used for.
Try this.
$query = "SELECT * FROM photographs INNER JOIN users ON photographs.id = users.id";
$result = mysql_query($query);
you cannot chain mysql queries in php that way. you have 2 options.
create a real mysql join.
you can use the shorthand syntax:
SELECT * FROM `photographs` p, `users` u WHERE p.id = u.id AND id=1
or a real join:
SELECT * FROM `photographs` p INNER JOIN `users` u WHERE p.id = u.id AND id=1
might i suggest reading more about mysql joins:
http://www.codinghorror.com/blog/2007/10/a-visual-explanation-of-sql-joins.html
I have a script designed to print out values of students who have accrued more than 3 tardies. I want this script to print out both the student name, and the amount of times they've been tardy, but so far I've been only able to print out their names with the following script:
$sql = "select DISTINCT StudentID,classid,date from attendance_main where status = 'Tardy' AND classid like '%ADV%'";
$result = mysql_query($sql) or die (mysql_error());
while($row=mysql_fetch_array($result)) {
$studentid = $row['StudentID'];
$sql2 = "select distinct StudentID,classid,date from attendance_main where StudentID = '$studentid' AND status = 'Tardy' AND classid like '%ADV%'";
$result2 = mysql_query($sql2) or die (mysql_error());
while($row2=mysql_fetch_array($result2)) {
$tardycount = mysql_num_rows($result2);
$studentid = $row2['StudentID'];
if($tardycount >= 3) {
$sql3 = "select * from students where rfid = '$studentid'";
$result3 = mysql_query($sql3) or die (mysql_error());
while($row3=mysql_fetch_array($result3)) {
$fname[] = $row3['fname'];
}
}
}
}
$newdata = array_unique($fname);
foreach ($newdata as $value) {
echo $value;
}
I can't think of how to intuitively do this. Keeping it all in the while loop didn't work (I had multiple results coming up for the same students despite requesting unique entries) so using array_unique was the only method I could think of.
Thanks for any help!
Something like this:
SELECT
attendance_main.StudentID,
students.fname,
COUNT(attendance_main.*) AS `times_tardy`
FROM
attendance_main
INNER JOIN
students
ON
attendance_main.StudentID = students.rfid
WHERE
attendance_main.status = 'Tardy'
AND
attendance_main.classid like '%ADV%'
GROUP BY
attendance_main.StudentID
HAVING
`times_tardy` > 3
Joining the two tables gets you the tardy count and student's name in one query, and the GROUP BY and HAVING clause that get you only the students with more than 3 tardy entries.
You can (and should) do almost everything in SQL. It should look something like this.
select StudentID, classid, date count(*)
from attendance_main
where status = 'Tardy' AND classid like '%ADV%'"
left join student on student.rfid = attendance_main.StudentId
group by StudentId
having count(*) > 3;
Here's how it works.
select the results you want to work with:
select StudentID, classid, date count(*)
from attendance_main
where status = 'Tardy' AND classid like '%ADV%'"
Join the students to your result set on the common id
left join student on student.rfid = attendance_main.StudentId
group everything by student. We use count(*) to get the number of items. We know we're only dealing with tardies because of the where clause in the select.
group by StudentId
limit the results to only tardies above 3 with the having claues (this is like a where clause for the group by)
having count(*) > 3;