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
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 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';
I have a system where I getting images out of my database, but when it does that, there is 3x of the same images.
I have tried with different ways, DISTINCT and such, but I have no clue how I fix this.
Here is my query code:
<?php
$id = $_GET['id'];
$query = "SELECT DISTINCT * FROM billeder INNER JOIN album ON fk_album_ID = $id";
$result = mysqli_query($con, $query);
while($row = mysqli_fetch_assoc($result))
{
$thumb_src = 'billeder/thumb_'.$row['billeder_sti'];
$full_src = 'billeder/'.$row['billeder_sti'];
echo "
<div class='ikon'>
<a href='$full_src'>
<img src='$thumb_src' alt='' />
</a>
</div>
";
}
?>
Hope someone can help me on the way to fix this :)
Without being able to see your table structure I won't be able to give an exact answer but the likely reason is because your INNER JOIN is not setup correctly.
SELECT DISTINCT *
FROM billeder
INNER JOIN album
ON (billeder.fk_album_ID = album.pk_album_ID)
WHERE
billeder.fk_album_ID = $id
Something like the above would be the correct way to JOIN a table and using a WHERE clause to then limit the date received.
JOIN must be used with two tables columns. See example:
SELECT * FROM tableA a INNER JOIN tableB b ON a.id = b.a_id;
What you're trying to make is something like this:
"SELECT DISTINCT * FROM billeder INNER JOIN album ON
billeder.fk_album_ID = album.album_id WHERE billeder.id = $id"
You shouldn't pass an argument to the JOIN. The arguments must be used on the WHERE clause.
<?php
include 'dbFunctions.php';
$courseid = $_GET['Course_id'];
$query = "SELECT * FROM course WHERE Course_id=".$courseid."";
$arrCourse = executeSelectQuery($query);
$query2 = "SELECT * FROM course_member WHERE Course_id=".$courseid."";
$result = mysqli_query($link,$query2) or die(mysqli_error($link));
?>
HTML body:
<?php
while ($row = mysqli_fetch_array($result)) {
?>
<?php echo $row['member_id']
?>
<?php
}
?>
this correctly prints the results of the member id that is involved in the selected course, however, i want to extract the first_name using the result generated that belong to another table called member.
been trying all the join queries but it didn't work.
Sounds like you need to read up on the JOIN operation in SQL. The following query will return all the data you seem to need, from a single query:
SELECT *
FROM course
INNER JOIN course_member ON course.id = course_member.course_id
INNER JOIN member ON member.id = course_member.member_id
As far as I see
$sql="select last_name from course_member
join member on course_member.member_id = member.member_id
where course_member.Course_id = ".$courseid;
I'm going to take a guess here at your table defs...
$query2 = "SELECT m.first_name, cm.* FROM course_member cm join member m on m.id = cm.member_id WHERE Course_id=".$courseid."";
If you want only the member name and you are not much interested with the id then you can merge it into a single query
$query = SELECT fName from member WHERE id = (SELECT member_id FROM course_member WHERE Course_id=$courseid);
Here I'm making two queries with PHP. Is there something more simple? One query instead of two?
$id = mysql_real_escape_string($_GET["id"]);
$result = mysql_query("SELECT * FROM questionstable WHERE id=$id");
$row = mysql_fetch_assoc($result);
$category = $row['category'];
$main = mysql_query("SELECT name FROM categorytable WHERE id=$category");
SELECT questionstable.*, categorytable.name
FROM questionstable
INNER JOIN categorytable
ON categorytable.id = questionstable.category
WHERE questionstable.id=$id
As an aside, assuming your questionstable.id is numeric, you could use $id = (int)$_GET["id"] and save some writing. (It's also probably a safer bet. Just because it's escaped doesn't mean it's completely safe--especially when it's not within quotes [gives you a LOT of options for SQL injection]. ;-))
Please try:
SELECT name
FROM categorytable
WHERE id = (
SELECT category
FROM questionstable
WHERE id = $id
)
$id = mysql_real_escape_string($_GET["id"]);
$main = mysql_query("SELECT c.name FROM categorytable c inner join questionstable q on c.category = q.category WHERE q.id = $id");
Do not use inner join use left join instead, it won't return any result if the category is not found
SELECT questionstable.*, categorytable.name
FROM questionstable
LEFT JOIN categorytable
ON categorytable.id = questionstable.category
WHERE id=$id