genzedu777 Posted January 22, 2011 Share Posted January 22, 2011 Hi all, Perhaps, let me briefly explain what I would like to achieve. Currently I am using INNER JOIN command to link 4 sql tables 1) tutor_overall_level_subject.sql 2) tutor_subject_level.sql 3) tutor_level.sql 4) tutor_subject.sql In tutor_level.sql, there are 11 'level_id' level id 1 == Pre-School level id 2 == Lower Primary School level id 3 == Upper Primary School level id 4 == Lower Secondary etc.... As you can see from the code below, I am trying to retrieve 'lower primary' records only and place it in a table Subsequently, 'upper primary' records and place it in another table However when I executed the code, I receive a blank page. What could have gone wrong? Thanks if ($row3['level_id'] == 2){} if ($row3['level_id'] == 3){} <?php //Retrieve Lower Primary if ($row3['level_id'] == 2) { echo'<table><tr>'; echo '<td class="label">Lower Primary</td>'; $count = 0; while($row3 = mysqli_fetch_array($data3)) { if ($count % 5 == 0) { echo "</tr><tr>"; $count = 0; } echo '<td>' . $row3['subject_name'] . '</td>'; $count++; } echo '</tr></table><br/>'; } //Upper Lower Primary if ($row3['level_id'] == 3) { echo'<table><tr>'; echo '<td class="label">Upper Primary</td>'; $count = 0; while($row3 = mysqli_fetch_array($data3)) { if ($count % 5 == 0) { echo "</tr><tr>"; $count = 0; } echo '<td>' . $row3['subject_name'] . '</td>'; $count++; } echo '</tr></table><br/>'; } ?> //This is my complete code <?php $query3 = "SELECT sl.level_id, sl.subject_id, tl.level_name AS level_name, ts.subject_name AS subject_name " . "FROM tutor_overall_level_subject AS ols " . "INNER JOIN tutor_subject_level AS sl USING (subject_level_id) " . "INNER JOIN tutor_level AS tl USING (level_id) " . "INNER JOIN tutor_subject AS ts USING (subject_id) " . "WHERE ols.tutor_id = '" . $_GET['tutor_id'] . "'"; $data3 = mysqli_query($dbc, $query3) or die(mysqli_error($dbc)); if (mysqli_num_rows($data3) > 0) { echo '<div id="panel4">'; if ($row3['level_id'] == 2) { echo '<td class="label">Lower Primary</td>'; echo'<table><tr>'; $count = 0; while($row3 = mysqli_fetch_array($data3)) { if ($count % 5 == 0) { echo "</tr><tr>"; $count = 0; } echo '<td>' . $row3['subject_name'] . '</td>'; $count++; } echo '</tr></table><br/>'; } echo '</div>'; //End of panel 4 ?> Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/ Share on other sites More sharing options...
genzedu777 Posted January 22, 2011 Author Share Posted January 22, 2011 Oh and there is another thing, I tried using var_dump() command and realised I have a returned value of 'bool(false) ' for 'if (var_dump($row3['level_id'] == 2))'. What could have caused it to be false? Thanks Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163414 Share on other sites More sharing options...
trq Posted January 22, 2011 Share Posted January 22, 2011 What could have caused it to be false? var_dump doesn't return any value. The problem your having is that $row3 isn't defined yet where you are trying to use it. Your basically doing.... if ($row3) { // code that defines $row3 } It makes no sense. Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163416 Share on other sites More sharing options...
genzedu777 Posted January 22, 2011 Author Share Posted January 22, 2011 Hi Thorpe, Thanks for your reply. May I check with you, what do you mean that I have yet defined the $row3? Correct me if I am wrong, in my $query3, I have queried sl.level_id AS level_id, which I believe there are already values in it, therefore when I execute '$row3['level_id'] == 2', why isn't it able to pull out data which has level_id == 2? Thanks $query3 = "SELECT sl.level_id AS level_id, sl.subject_id, tl.level_name AS level_name, ts.subject_name AS subject_name " . "FROM tutor_overall_level_subject AS ols " . "INNER JOIN tutor_subject_level AS sl USING (subject_level_id) " . "INNER JOIN tutor_level AS tl USING (level_id) " . "INNER JOIN tutor_subject AS ts USING (subject_id) " . "WHERE ols.tutor_id = '" . $_GET['tutor_id'] . "'"; Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163425 Share on other sites More sharing options...
trq Posted January 22, 2011 Share Posted January 22, 2011 Because you don't define $row3 until here.... while($row3 = mysqli_fetch_array($data3)) { this is within your if, so never actually gets executed. You need to move your if statements into the while loop. Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163429 Share on other sites More sharing options...
genzedu777 Posted January 22, 2011 Author Share Posted January 22, 2011 Thanks Thorpe, I got the idea already. It works now. One last question. echo ''.$row3['subject_name'].', '; As I did an echo for the subject name in the while loop and realised the last result will still have a comma, example English, Math, Science, Chinese, How do I code to prevent the last value to have a comma? I would like to achieve English, Math, Science, Chinese <--Without the comma at the last value. Thanks $data3 = mysqli_query($dbc, $query3) or die(mysqli_error($dbc)); if (mysqli_num_rows($data3) > 0) { echo '<div id="panel4">'; echo '<span class="row_header">Lower Primary</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 2) { echo ''.$row3['subject_name'].', '; } } echo '</div>'; //End of panel 4 } //End of IF for $query and $data (Teaching Subjects) Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163433 Share on other sites More sharing options...
genzedu777 Posted January 22, 2011 Author Share Posted January 22, 2011 Hi Thorpe, There is another issue which I am facing Currently executing the code below, it gives me a nice organized results, attachment in correct.jpg echo '<span class="row_header">Lower Primary</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 2) { echo ''.$row3['subject_name'].', '; } } However after adding a duplicated code for 'Upper Primary', my results return in a warp manner, in attachment incorrect.jpg. Did I place my code wrongly? How do I achieve correct.jpg format for 'Upper Primary'? Thanks <?php //Lower Primary echo '<span class="row_header">Lower Primary</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 2) { echo ''.$row3['subject_name'].', '; } //Upper Primary echo '<span class="row_header">Upper Primary</span><br/>'; if ($row3['level_id'] == 3) { echo ''.$row3['subject_name'].', '; } } ?> [attachment deleted by admin] Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163437 Share on other sites More sharing options...
genzedu777 Posted January 22, 2011 Author Share Posted January 22, 2011 Hi all, I need some help here. Been trying to get this right Currently when I executed the code below, I will have a return value of Lower Primary English, Mathematics, Science, Chinese, echo '<span class="row_header">Lower Primary</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { [color=red]if ($row3['level_id'] == 2)[/color] { echo ''.$row3['subject_name'].', '; } } And I have decided to add the similar code for 'Upper Primary'. After adding the Upper Primary code, my return result is still Lower Primary English, Mathematics, Science, Chinese, I don't see 'Upper Primary' result appearing. Any advice? Thanks echo '<span class="row_header">Lower Primary</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 2) { echo ''.$row3['subject_name'].', '; } } echo '<br/>'; //Upper Primary while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 3) { echo ''.$row3['subject_name'].', '; } } Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163559 Share on other sites More sharing options...
BlueSkyIS Posted January 22, 2011 Share Posted January 22, 2011 if you're going to loop over the result twice, you'll need to reset it before the second time. while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 2) { echo ''.$row3['subject_name'].', '; } } echo '<br/>'; mysql_data_seek($data3, 0); // Move internal result pointer back to first record. //Upper Primary while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 3) { echo ''.$row3['subject_name'].', '; } } Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163611 Share on other sites More sharing options...
genzedu777 Posted January 23, 2011 Author Share Posted January 23, 2011 Hi all, Is there anyone that can give me advice for the thread which I have posted yesterday? Many Thanks!!! Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163810 Share on other sites More sharing options...
genzedu777 Posted January 23, 2011 Author Share Posted January 23, 2011 Hi BlueSkyIs, Sorry that I didnt see you post. Omg! It works! Thanks!!!! One last question, I have asked before, but didnt received an answer yet. Currently my result displayed a 'comma' at the end Lower Primary English, Math, Science, Chinese, How do I remove the comma which is bold in red? Thank you so much while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 2) { echo ''.$row3['subject_name'].', '; } } Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163963 Share on other sites More sharing options...
genzedu777 Posted January 23, 2011 Author Share Posted January 23, 2011 There is another issue here. Currently the user did not select any subjects in pre-school, therefore there isnt any value, however the header will still show 'Pre-School' with empty value. Attached is the picture for your reference. How do code, so that only the 'level_id' which has value or selected by users will appear? Do I user (!empty) command? I tried, but it gives an error. Anyone can help me out with this? Error Code //Pre-School echo '<span class="row_header">Pre-School</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if (!empty($row3['level_id'] == 1)) { echo ''.$row3['subject_name'].', '; } } echo '<br/><br/>'; Current workable code, but still trying to not show Pre-School, cuz it doesnt have any selected value <?php //Pre-School echo '<span class="row_header">Pre-School</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 1) { echo ''.$row3['subject_name'].', '; } } echo '<br/><br/>'; mysqli_data_seek($data3, 0); //Lower Primary echo '<span class="row_header">Lower Primary</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 2) { echo ''.$row3['subject_name'].', '; } } echo '<br/><br/>'; mysqli_data_seek($data3, 0); // Move internal result pointer back to first record. //Upper Primary echo '<span class="row_header">Upper Primary</span><br/>'; while($row3 = mysqli_fetch_array($data3)) { if ($row3['level_id'] == 3) { echo ''.$row3['subject_name'].', '; } } ?> [attachment deleted by admin] Link to comment https://forums.phpfreaks.com/topic/225277-if-command-query-doesnt-work/#findComment-1163974 Share on other sites More sharing options...
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