Foreach loop in php mysql

Question

Following code is fine to retrieve relevant result from DB. But when result is null, It shows

Notice: Undefined variable: myArrayOfemp_id in Warning: Invalid argument supplied for foreach() in .

$result1 = "SELECT leave_id FROM emp_leaves where duty_assign=".$userID;
$array = mysql_query($result1);
$cnt = 0;
while ($row = mysql_fetch_array($array)) {
    $myArrayOfemp_id[$cnt] = $row[0];
    $cnt++;
}
// var_dump($myArrayOfemp_id);

$sql = "SELECT * FROM emp_leaves WHERE ";
foreach ($myArrayOfemp_id as $value)  {
    $sql .= " leave_id={$value} || ";
}
$sql .= "1=2";
$result = mysql_query($sql);
$total_results = mysql_num_rows($result);

How can I avoid from displaying that error. Please help !

why this `sql .= "1=2";` ? it will always give emptyresult. – Niklesh Raut Jun 03 '16 at 09:44 — Niklesh Raut, Jun 03 '16 at 09:44

score 1 · Accepted Answer · answered Jun 03 '16 at 09:40

1

Just initialize array $myArrayOfemp_id before while loop

$myArrayOfemp_id = array();
while ($row = mysql_fetch_array($array)) {
      $myArrayOfemp_id[$cnt] = $row[0];
      $cnt++;
}

answered Jun 03 '16 at 09:40

Dhara Parmar

8,021
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score 1 · Answer 2 · edited May 23 '17 at 12:15

1

you also should make sure to escape your strings before putting them in the query. see here for a better explanation How to include a PHP variable inside a MySQL insert statement

And before the while loop you should check with mysql_num_rows() if there are any results.

edited May 23 '17 at 12:15

Community

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1

answered Jun 03 '16 at 09:48

Christian Dornbusch

105
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Let me know how can I give ORDER BY condition to query of in foreach – Chathurika Jun 03 '16 at 10:08
1

just do it after the last query string: `$sql .= "1=2";` Like this: `$sql .= " ORDER BY leave_id"; – Christian Dornbusch Jun 03 '16 at 10:10
Thank u in advance for your answer, – Chathurika Jun 03 '16 at 10:15

score 1 · Answer 3 · answered Jun 03 '16 at 09:57

1

Hi First why you are using "1=2" it should be 1=1. Second always define array before using it so define $myArrayOfemp_id = array(); before while loop.

For sake of correct ouput please print your $sql before executing is means. echo $sql; and run the resultant query in Phpmyadmin

answered Jun 03 '16 at 09:57

Passionate Coder

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I changed it as 1=1, Another thing is how can I give ORDER BY condition to query of in foreach – Chathurika Jun 03 '16 at 10:05
1

@Chathurika just write this line $sql .= "1= 1 ORDER BY leave_id" or $sql .= "1= 1 ORDER BY leave_id DESC" according to your sorting order – Passionate Coder Jun 03 '16 at 10:18

Foreach loop in php mysql

3 Answers3