IF command query doesn't work

[genzedu777]

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
?>

 

 

 

[genzedu777]

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

[trq]

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.

[genzedu777]

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'] . "'";

[trq]

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.

[genzedu777]

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)

[genzedu777]

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]

[genzedu777]

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'].', ';

}

}

 

[BlueSkyIS]

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'].', ';
         }
      }

[genzedu777]

Hi all,

 

Is there anyone that can give me

advice for the thread which I have posted yesterday? Many Thanks!!!

[genzedu777]

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'].', ';
         }
      }

[genzedu777]

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]