PHP - doesn`t show anything with mysqli_fetch_assoc in while-loop

Question

I want to give some data from a MySQL database to a Android App via JSON.

So far i have written this php script to give me the JSON object:

$result = mysqli_query($con,"SELECT * FROM job");

$row = mysqli_fetch_assoc($result); 

while($row = mysqli_fetch_assoc($result)){
  $output[] = $row;
}

print(json_encode($output));

I have found out by accident that when I dont add the line "$row = mysqli_fetch_assoc($result);" before the while-loop it doesn`t return anything. But when I do add this line like in the example the JSON object doesnt contain the first element.

I believe its because of this line where $row already contains the first line.

Hopefully you can help me :)

How many rows is it returing? Insert this after the query : echo mysqli_num_rows($result);. You have to remove the line $row=mysqli_fetch_assoc($result);. — Jose Manuel Abarca Rodríguez
– Jose Manuel Abarca Rodríguez, Commented Oct 20, 2016 at 20:58
not possible. PHP doesn't care where/how you do the fetch call. whether it's inside the while or just before it, you'll STILL be fetching a row from the db. all you're doing is throwing away that first row, unless you ALSO have $output[] = $row; before the while starts. — Marc B
– Marc B, Commented Oct 20, 2016 at 21:01
when I dont add the line before the while-loop it doesn`t return anything Unpossible..... — AbraCadaver
– AbraCadaver, Commented Oct 20, 2016 at 21:04

cn0047 · Accepted Answer · 2017-08-28 14:14:31Z

1

With purpose to figure out what wrong with your query you have to do something like this:

if ($result = mysqli_query($db, $sql)) {
    // Here you can see and check count of rows in your result set.
    $numRows = mysqli_num_rows($result);
    // ...
} else {
    // Here you can see and check and understand error.
    var_export(mysqli_error($db));
}

with purpose to traverse all your rows from result set you have to do:

while ($row = mysqli_fetch_assoc($result)) {
    var_export($row);
}

and you must not have $row = mysqli_fetch_assoc($result) before while loop.

answered Aug 28, 2017 at 14:14

cn0047

17.2k7 gold badges61 silver badges75 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

PHP - doesn`t show anything with mysqli_fetch_assoc in while-loop

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related