Query error displayed when trying to retrieve data

[heshan]

Hi All,

 

I want to retrieve time table data for viewing purposes for the teachers. Here i have created this form, but it throws 2 types errors.

 

1). Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\wamp\www\teachers\sudent  attendance\tviewStudentAttendanceForm.php on line 151

 

2.) Notice: Uninitialized string offset: 1 in C:\wamp\www\teachers\sudent attendance\tviewStudentAttendanceForm.php on line 163.

 

I know error 1 usually comes when a user try to reuse an existing variable ($result) inside a while loop. But i have fixed it by giving different names. But still the error displays as it is. I have no idea about the error number 2. Please help me out.

 

<?php
	  
$state_i='';
$state_id='';
	   
        
if($stream!=null){

$query1="select class_id  from class
         where class.grade_id='$grade' and class.class_name='$class' and class.stream='$stream'";
}else{

$query1="select class_id  from class
         where class.grade_id='$grade' and class.class_name='$class'";
}
$result1=mysql_query($query1);
		while($row1=mysql_fetch_array($result1)){
$class_id=$row1['class_id']; }


$query="SELECT student_class.admission_no,student_info.name_with_initial FROM student_info INNER JOIN student_class ON student_info.admission_no=student_class.admission_no
		where  student_class.year='$year' and student_class.class_id='$class_id'";
$result=mysql_query($query);
	   $x=0;
	   
          while($row=mysql_fetch_array($result)){
			$x++;

			$admission_id[$x]=$row['admission_no'];
			$name[$x]=$row['name_with_initial'];

	  }


		for ($i=1;$i<=$x;$i++)
		{
$query2 = "select attendance_state.state,attendance_state.state_id from attendance_state inner join attendance on attendance_state.state_id=attendance.state_id where attendance.admission_no='".$admission_id[$i]."' and attendance.date='$date'";
$result2=mysql_query($query2);
                //Line 151
 			while($row2=mysql_fetch_array($result2)){

			 $state_i[$i]=$row2['state'];
			 $state_id[$i]=$row2['state_id'];
			 }}



		for($y=1;$y<=$x;$y++){
            echo"<tr>";
		echo"<td width='127' align='center'>".$admission_id[$y]."</td>";
		echo"<td width='274' align='center'>".$name[$y]."</td>";?>
            
            //Line 163
		<td width='103' align='center'><?php if($state_i[$y]=='pf'){ echo "present fullday";}if($state_i[$y]=='ph'){ echo "present halfday";}if($state_i[$y]=='ab'){ echo "absent";} ?></td><?PHP
	echo"</tr>";
	  }
          ?>

[Pikachu2000]

A query is failing, and since you don't have any logic in place to make sure the queries succeed, you're passing a boolean FALSE to mysql_fetch_array(). Echoing (or logging) the error from mysql_error() and the query string that caused the error would be a good place to start.

[Jessica]

The first error is being cause by your query failing.

Look at the examples on mysql_query, and you'll want to print the error and the SQL so you can debug what's wrong with your query.

 

Edit: On preview, what pikachu said. I'm just going to leave this here for the link to the examples.

[heshan]

It says " Unknown column 'attendance_state.state' in 'field list' " in the following query. But i do not see anything wrong here. My attendance_state table looks like this.

 

attendance_state (state_id, state)

 

$query2 = "select attendance_state.state_id,attendance_state.state from attendance_state inner join attendance on attendance_state.state_id=attendance.state_id where attendance.admission_no='".$admission_id[$i]."' and attendance.date='$date'";
$result2=mysql_query($query2) or die (mysql_error());