PHP: table structure - php

I'm developing a website that has some audio courses, each course can have multiple lessons. I want to display each course in its own table with its different lessons.
This is my SQL statement:
Table: courses
id, title
Table: lessons
id, cid (course id), title, date, file
$sql = "SELECT lessons.*, courses.title AS course FROM lessons INNER JOIN courses ON courses.id = lessons.cid GROUP BY lessons.id ORDER BY lessons.id" ;
Can someone help me with the PHP code?
This is the I code I have written:
mysql_select_db($database_config, $config);
mysql_query("set names utf8");
$sql = "SELECT lessons.*, courses.title AS course FROM lessons INNER JOIN courses ON courses.id = lessons.cid GROUP BY lessons.id ORDER BY lessons.id" ;
$result = mysql_query($sql) or die(mysql_error());
while ($row = mysql_fetch_assoc($result)) {
echo "<p><span class='heading1'>" . $row['course'] . "</span> </p> ";
echo "<p class='datum'>Posted onder <a href='*'>*</a>, latest update on " . strftime("%A %d %B %Y %H:%M", strtotime($row['date']));
}
echo "</p>";
echo "<class id='text'>";
echo "<p>...</p>";
echo "<table border: none cellpadding='1' cellspacing='1'>";
echo "<tr>";
echo "<th>Nr.</th>";
echo "<th width='450'>Lesso</th>";
echo "<th>Date</th>";
echo "<th>Download</th>";
echo "</tr>";
echo "<tr>";
echo "<td>" . $row['nr'] . "</td>";
echo "<td>" . $row['title'] . "</td>";
echo "<td>" . strftime("%d/%m/%Y", strtotime($row['date'])) . "</td>";
echo "<td><a href='audio/" . rawurlencode($row['file']) . "'>MP3</a></td>";
echo "</tr>";
echo "</table>";
echo "<br>";
}
?>

One thing that comes to mind is you're starting with lessons and pulling the course details over with it. That means you're going to have a new row per lesson with a joined course. You may want to sort by course (so they're grouped) then (in PHP) keep a tally of "current course". When the course changes, switch to new heading paragraph, table, etc.
Pseudo code:
$currentCourse = null; // intitialize the course
$query = your select sorted by course;
while ($row in $query)
{
if ($currentCourse != $row['course'])
{
if (!is_null($currentCourse))
{
// there was a course before it, close the current one
}
// begin setting up heading1, table beginning, etc.
$currentCourse = $row['course']; // set this as the active course
}
// dump the current row as a table entry
}
// close the table (same code as in the second if statement)

You close the while loop on line 8 of your code block. Remove that '}' on line 8.
Also the HTML element doesn't exists!
I think I know what's your problem. You need a while loop that loops al the "courses" and in that loop you execute a second query where you select the lessons where the course_id is equal to the current course id you're looping. A little dummy code for you.
<?php
while($row = mysql_fetch_assoc(mysql_query("SELECT * FROM courses"))) {
//display the course
while($row2 = mysql_fetch_assoc(mysql_query("SELECT * FROM lessons WHERE course_id=" . $row['id']))) {
//display the lessons of that course
}
}
?>

Related

How do i loop through but replace missing data with blanks in table

I am trying to display a table to show all the subjects the first student takes, then all the progress grades the student has made in that subject.
However, a student may not have a grade in a certain column so i need to place a blank or 'no grade' in place of it.
Instead i get them stacked side by side...
As you can see below '7(Pc3)' in English should be in the 'PC3' column and 'PC2' should say no grade or blank.... If possible -
Thanks
I have the loop working to fetch the students, plus the loop working to fetch all the subjects for that student.
And can display all the grades - but they don't line up with the right column
while ($res = $result->fetch_assoc()) {
echo "<tr><td>" . $res['subname'] . "</td>";
$result2 = mysqli_query($mysqli, "SELECT *
FROM grades
JOIN gradesets ON grades.gradeset_id = gradesets.id
WHERE grades.student_id = {$row['id']}
AND grades.subject_id = {$res['id']}
ORDER BY grades.gradeset_id ") or die($mysqli->error);
while ($res2 = $result2->fetch_assoc()) {
echo "<td>" . $res2['grade'] . "</td>";
//echo "<td>" . $res2['gradeset_id'] . "</td>";
//print_r($res2);
$resset = $res2['gradeset'];
$resset2 = substr($resset, -1);
//print_r($resset);
//print_r($resset2);
}
}
So i can echo out the right grades, but need to test they match up in the right columns... Here is the full code if needed...
$student = $mysqli->query("SELECT * FROM student");
echo "<center>";
echo "<h2>Data Wall</h2>";
echo "<h3>PHP</h3>";
echo "<hr/>";
while ($row = $student->fetch_assoc()) {
echo "<table border='1'>
<tr>
<th>ID</th>
<th>STUDENT</th>
<th>HOUSE</th>
</tr><br>";
echo "<tr>";
echo "<td>" . $row['id'] . "</td>";
echo "<td>" . $row['stuname'] . "</td>";
echo "<td>" . $row['house'] . "</td>";
echo "</tr><br><tr></tr><tr></tr><tr></tr><tr></tr><tr></tr><tr></tr><tr></tr>";
echo "<tr><th>SUBJECTS</th><th>PC1</th><th>PC2</th><th>PC3</th><th>PC4</th></tr>";
$result = mysqli_query($mysqli, "SELECT subjects.id,subjects.subname
FROM student
JOIN grades ON student.id = grades.student_id
JOIN subjects ON subjects.id = grades.subject_id
WHERE student.id = {$row['id']}
GROUP BY subjects.subname ORDER BY subjects.id ") or die($mysqli->error);
while ($res = $result->fetch_assoc()) {
echo "<tr><td>" . $res['subname'] . "</td>";
$result2 = mysqli_query($mysqli, "SELECT *
FROM grades
JOIN gradesets ON grades.gradeset_id = gradesets.id
WHERE grades.student_id = {$row['id']}
AND grades.subject_id = {$res['id']}
ORDER BY grades.gradeset_id ") or die($mysqli->error);
while ($res2 = $result2->fetch_assoc()) {
echo "<td>" . $res2['grade'] . "</td>";
//echo "<td>" . $res2['gradeset_id'] . "</td>";
//print_r($res2);
$resset = $res2['gradeset'];
$resset2 = substr($resset, -1);
//print_r($resset);
//print_r($resset2);
}
}
}
echo "</tr>";
echo "</table>";
echo "</center>";
$mysqli->close();
?>
Since PHP 5.3 you can use Elvis operator - ?:
And since PHP 7 you are able to use Null Coalescing Operator - ??
Either of these you can use to display some other information if you row is empty. For example (PHP 7+):
echo "<td>" . ($res2['grade'] ?? 'No grade') . "</td>";
Would result to either a grade, or No grade text if string is empty or false.
Hope this helps!
In your inner query, you're doing an INNER JOIN, which selects only those rows that have a match in the gradeset table. It looks like you want a LEFT OUTER JOIN, so that you get null placeholders where there is no match:
SELECT *
FROM grades
LEFT JOIN gradesets ON grades.gradeset_id = gradesets.id
WHERE grades.student_id = {$row['id']}
AND grades.subject_id = {$res['id']}
ORDER BY grades.gradeset_id
This way, in your query result, instead of getting:
4 (PC1)
7 (PC3)
6 (PC4)
You'll get:
4 (PC1)
null
7 (PC3)
6 (PC4)
You could build an array of empty grades and then replace them with any data from the query. Like so:
$grades = [1 => '', 2 => '', 3 => '', 4 => ''];
while ($res2 = $result2->fetch_assoc()) {
$grades[$res2['gradeset']] = $res2['grade'];
}
foreach ($grades as $grade) {
echo "<td>" . $grade . "</td>";
}

php - How to find out the order no. of a row while displaying values?

I have code that takes values from a database that belong to a particular user.
<?php
$user = $_SESSION['username'];
$q = intval($_GET['q']);
$db = mysqli_connect('localhost', 'username', 'password', 'database_name');
$sql = "SELECT * FROM savedtimes WHERE username = '$user' AND session = '$q' ORDER BY timeid";
$result = mysqli_query($db, $sql);
//$SNo = I might need to put something over here which makes it show the order number.
echo "<table>
<tr>
<th>S.No.</th>
<th>time</th>
<th>Avg of 5</th>
</tr>";
while($row = mysqli_fetch_array($result)) {
echo "<tr>";
echo "<td>" . $SNo . "</td>";//This is the S.no column.
echo "<td>" . $row['value2'] . "</td>";
echo "</tr>";
}
echo "</table>";
?>
Now, while it is displaying these values in the order of a field called timeid, which is on auto increment, I want to have a column called S.No (only while displaying, not in the actual database), which orders them from 1 to the last number. Please note that I can't just use 'timeid', because I have multiple users, so the numbers won't be continuous. So basically, the order is that of 'timeid', but I want a column showing up with continuous numbers. How do I do this?
Declare a counter variable (with a value of 1) outside of the while() loop. Display it inside the loop and subsequently increment it at the end of the loop.
// your code
$SNo = 1;
while($row = mysqli_fetch_array($result)) {
echo "<tr>";
echo "<td>" . $SNo . "</td>";
echo "<td>" . $row['value2'] . "</td>";
echo "</tr>";
++$SNo;
}
// your code

Trying to order a 3 table JOIN by date desc, How to sort correctly?

Have 3 different mysql tables, my script queries the DB using JOINS to output the most recent results from each of the 3 tables. All works like it is supposed to but the way mysql databases allow for JOINS, the ORDER BY will order the results as you list the tables, resulting in the finished output not being ordered by date correctly, since the results are from 3 different MYSQL tables.
The results instead are ordered by date correctly only next to the other results form the same table. See the script and results below: (I am limit 1 for the output for simplicity)
$username = $_SESSION['username'];
$result = $mysqli->query("
SELECT
accounts.account_name,
cases.case_subject,
tasks.task_title,
accounts.accounts_date_last_edited,
cases.cases_date_last_edited,
tasks.tasks_date_last_edited
FROM
accounts,
cases,
tasks
WHERE
accounts.username = cases.username
AND cases.username = tasks.username
ORDER BY
accounts.accounts_date_last_edited DESC,
cases.cases_date_last_edited DESC,
tasks.tasks_date_last_edited DESC
LIMIT 1
");
if (!$result) { echo "Error Result5: " . $mysqli->error; } else {
echo "<table>";
echo "<tr><th>Item</th><th>Date</th></tr>";
while ($row = $result->fetch_array(MYSQLI_ASSOC))
{
echo "<tr>";
echo "<td>" . $row['account_name'] . "</td><br>";
echo "<td>" . $row['accounts_date_last_edited'] . "</td><br>";
echo "</tr>";
echo "<tr>";
echo "<td>" . $row['case_subject'] . "</td><br>";
echo "<td>" . $row['cases_date_last_edited'] . "</td><br>";
echo "</tr>";
echo "<tr>";
echo "<td>" . $row['task_title'] . "</td><br>";
echo "<td>" . $row['tasks_date_last_edited'] . "</td><br>";
echo "</tr>";
}
echo "</table>";
The Results are below: they will list 1 item from each table listed above. Again I am trying to sort by the date_last_edited regardless of which table the values are from.
Item Date
Shorley Homes 2013-11-02 04:02:34
Techical Testing Case Open 2013-11-03 07:17:36
Icons 2013-11-03 07:28:02
If I read correctly (and I'm not sure of that) your
...sort by the date_last_edited regardless of which table the values are from...
then you might want to use UNION instead of JOIN
SELECT account_name item, accounts_date_last_edited date
FROM accounts
UNION ALL
SELECT case_subject, cases_date_last_edited
FROM cases
UNION ALL
SELECT task_title, tasks_date_last_edited
FROM tasks
ORDER BY date DESC
Here is SQLFiddle demo

How to get the value from the primary key AND foreign key when joining mySQL tables?

I have two tables, employee as the parent and license as the child. They both have a Lic_ID column for reference, this column is the PK in license and the FK in employee. The license table also has a column Lic_Type which holds the name of the license.
I am trying to create a table with list boxes so the employee table can be updated. The list box value needs to be populated with the license.Lic_ID and the license.Lic_Type is to be displayed in the option. Here is what I have:
(Employee name, Id, etc. called out up here)
<?php
echo "<select name=\"Lic\">";
echo "<option value=\"\">Select...</option>";
$sql = $mysqli->query("SELECT Lic_ID, Lic_Type FROM license");
while($row = $result->fetch_assoc())
{
echo "<option value=\"" . $row['Lic_ID'] . "\">" . $row['Lic_Type'] . "</option>";
}
echo "</select>";
?>
So that works good, it shows the license type and has the value set to the license id. What I want to do is have <option selected="selected"> if the license id is set for an employee. This code doesn't work, but I think it illustrates what I'm trying to do:
<?php
echo "<select name=\"Lic\">";
echo "<option value=\"\">Select...</option>";
$sql = $mysqli->query("SELECT license.Lic_ID, license.Lic_Type, employee.Lic_ID FROM employee INNER JOIN license ON employee.Lic_ID = license.Lic_ID");
while($row = $result->fetch_assoc())
{
echo "<option value=\"" . $row['license.Lic_ID'] . "\"";
if($row['employee.Lic_ID'] = $row['license.Lic_ID']){echo "selected=\"selected\";}
echo ">" . $row['license.Lic_Type'] . "</option>";
}
echo "</select>";
?>
Is there a way to accomplish what I'm trying to do?
I think there may have been some confusion on what exactly I was trying to accomplish, I apologize for not being very clear. Anyways, I stumbled over the answer today, so I thought I should post it.
$sql1 = ("SELECT Emp_Name, Lic_MAT_ID FROM employee");
if(!$result_employee_query = $mysqli->query($sql1))
{
die ("There was an error getting the records from the employee table");
}
while($employee = $result_employee_query->fetch_assoc())
{
echo "Employee Name: " . $employee['Emp_Name'] . "<br>";
echo "License: ";
echo "<select>";
$sql2 = ("SELECT Lic_MAT_ID, Lic_MAT_Type FROM license_mat");
if(!$result_license_query = $mysqli->query($sql2))
{
die ("There was an error getting the records from the license table");
}
while($license = $result_license_query->fetch_assoc())
{
echo "<option value=\"" . $license ['Lic_MAT_ID'] . "\"";
if($license['Lic_MAT_ID'] == $employee['Lic_MAT_ID'])
{
echo " selected=\"selected\"";
}
echo ">" . $license ['Lic_MAT_Type'] . "</option>";
}
echo "</select><br>";
}
As I understand your problem: You want to see if the License has been added to ANY users or has it been unassigned. If any of the users have the license set then it's "selected", othervize not.
First you have to assign the keyword "multiple" to your select object to make it a listbox:
echo "<select name=\"Lic\" multiple=\"multiple\">";
Second: I would write this kind of query:
$sql = $mysqli->query("SELECT l.Lic_ID, l.Lic_Type, e.cnt FROM licence l left outer join (select Lic_id, count(*) cnt from employee group by Lic_id) e on l.Lic_ID=e.Lic_id");
It selects the Lic_ID, Lic_Type and the count of how many employees have the respective Lic_ID set to it (left outer join)
and in the code just check, if the count is higher then 0
if($row['cnt'] > 0){
echo "selected=\"selected\";
}

Why Isn't My Data Being Shown?

I have the following tables in my database:
Minutes: minute_id, subject, next_subject, approval, meeting_id
Agendas: agenda_id, subject, duration, approval, reason, meeting_id
I am using the following PHP code:
<?php
$result = mysql_query("SELECT * FROM Agendas INNER JOIN Minutes ON Minutes.meeting_id = Agendas.meeting_id WHERE Agendas.Approval = 'disapproved'")
or die(mysql_error()); ;
if (mysql_num_rows($result) == 0) {
echo 'You Have No New Messages';
} else {
while($info = mysql_fetch_array($result))
{
echo "<tr>";
echo "<td><br/>" .'Title: '. $info['title']." </td>";
echo "<td><br/>" .'Approved?: '. $info['approval']. "</td>";
echo "<td><br/>" .'Reason: '. $info['reason']."</td>";
echo "<hr>";
}
}
echo "</tr>";
echo "</table>";
?>
I am not getting the desired data to be shown as I am only been presented with the message 'You Have No New Messages' when in the agendas table, there is a row which has a field disapproved!
Any ideas?
You are doing an INNER JOIN... make sure there is also an associated row in the minutes table, or else there will be no data to return, even if there is an entry in Agendas.

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