CODEWITHSUNDEEP
phpmysql
Andrew Walker
Andrew Walker

Reputation: 492

PHP while loop within a while loop works once

I have two queries sent to a database bring back posts (op_ideas 16 cols) followed by another which holds the votes per post (op_idea_vote cols 4) with matching idea_id's

Example of Data:

Query: op_ideas:

[{"idea_id":"2211","author_id":"100000", "date":"2012-09-06 10:02:28","idea_title":"Another test","4" etc etc

Query: op_idea_votes:

idea_id = 2211, agree=3, disagree=1, abstain=0

The code below ought to look at op_ideas, and then cycle over op_ideas_vote until it finds a match under 'idea_id'. Then it goes to the next record under op_ideas, and again using that idea_id search for it within the op_idea_vote list, find a match, and add it to the array.

This works for only the first record, not for the other three. I am testing, so I have 3 rows in each that match idea_id with different results in the op_idea_vote.

$votes = mysql_query($commentVotes);

$result = mysql_query($gl_query);

while ($gce_result = mysql_fetch_array($result)) {
    $voteid = $gce_result['idea_id'];

    while($allvotes= mysql_fetch_array($votes)) {
        if($voteid = $allvotes['idea_id']) 
        {
        //echo $voteid . " main idea and the votes: " . $allvotes;
            $gce_result["agree"] = $allvotes['agree'];
            $gce_result["disagree"] = $allvotes['disagree'];
            $gce_result["abstain"] = $allvotes['obstain'];
        } 
        else 
        {
            $gce_result["agree"] = 0;
            $gce_result["disagree"] = 0;
            $gce_result["abstain"] = 0;
        }
        //print_r($gce_result);
    }
    $data_result[] = $gce_result;
}

echo json_encode($data_result);

If I use print_f(&gce_result) it works fine in phpfiddle. But when i use the code above, it works for the first record, but it's complete missing the second two. It seems to be missing the second while, as it does not even give me the 0 0 0 results.

Query for op_ideas:

$gl_query = "SELECT DISTINCT * FROM heroku_056eb661631f253.op_ideas INNER JOIN op_organs ORDER BY date ASC;";
if (!mysql_query($gl_query)) {
    die('Error: ' . $gl_query . " " . mysql_error());
}
$result = mysql_query($gl_query);

Query For op_idea_vote :

$commentVotes = "SELECT v.idea_id, COUNT(v.agree = 1 or null) as agree, COUNT(v.disagree =   1 or null) as disagree, COUNT(v.obstain = 1 or null) as obstain FROM op_idea_vote v GROUP BY  v.idea_id";
if (!mysql_query($commentVotes)) {
    die('Error: ' . $commentVotes . " " . mysql_error());
}
$votes = mysql_query($commentVotes);

Upvotes: 2

Views: 550

Answers (3)

WayneC
WayneC

Reputation: 5740

Your problem is trying to scan over the $votes result more than once.

You should store the result of that query first.

Eg.

while ($vote = mysql_fetch_array($votes)) {
    $allvotes['idea_id'] = $vote;
}

while ($gce_result = mysql_fetch_array($result)) {
    $voteid = $gce_result['idea_id'];
    if (array_key_exists[$voteid, $allvotes]) {
       //assign results
    } else {
       //default
    }
}

Another option would be to do the query with a join, so you can do everything in one query. Then just loop over that result.

Upvotes: 0

Alvarez
Alvarez

Reputation: 1333

You can scan a resource only once. So the inner while will be run only one time.

Upvotes: 1

Ravindra Bagale
Ravindra Bagale

Reputation: 17675

use == instead of = for checking condition of if & while in the while loop ,you have to assign the value of $allvotes ,but you never assigned,

while ($gce_result == mysql_fetch_array($result)) {
    $voteid = $gce_result['idea_id'];

    while($allvotes== mysql_fetch_array($votes)) {
        if($voteid == $allvotes['idea_id']) 
        {
        //echo $voteid . " main idea and the votes: " . $allvotes;
            $gce_result["agree"] = $allvotes['agree'];
            $gce_result["disagree"] = $allvotes['disagree'];
            $gce_result["abstain"] = $allvotes['obstain'];
        } 
        else 
        {
            $gce_result["agree"] = 0;
            $gce_result["disagree"] = 0;
            $gce_result["abstain"] = 0;
        }
        $data_result[] = $gce_result;
    }

}

Upvotes: 0

Related Questions