Check if user exist with mysqli doesn't work

Question

$stmt = $db->prepare("SELECT * FROM user WHERE name='Steve Job'");
$stmt->execute();
if($stmt->num_rows){
    echo "1";
}

it return blank in my ajax callback. I've debugging for hours.

And you are sure you have a record where `name = 'Steve Job'` — Incognito, Feb 17 '14 at 09:44
you missed `$stmt->store_result();` after the `$stmt->execute();` — ponciste, Feb 17 '14 at 09:46
Probably because his name is Steve _Jobs_ :-) In any case, you could probably get away with `select 1` or `select count(*)` so s to avoid all of Steve's information having to come across the wire. There are precious few situations where `select *` makes sense, detecting the existence of a row is certainly not one of them. — paxdiablo, Feb 17 '14 at 09:49
@paxdiablo so instead of select all what you suggest? select name? — user3318525, Feb 17 '14 at 10:00
user3318525, I suggest `count(*)` - it should simply give you a single row holding a single value, no need to transfer a lot of stuff over the wire. This may become important when your DB server is a thousand kilometers away and there are ten million rows :-) — paxdiablo, Feb 17 '14 at 10:16
Does this answer your question? [How to check if a row exists in MySQL? (i.e. check if an email exists in MySQL)](https://stackoverflow.com/questions/22252904/how-to-check-if-a-row-exists-in-mysql-i-e-check-if-an-email-exists-in-mysql) — Dharman, Feb 14 '20 at 22:35

score 1 · Accepted Answer · answered Feb 17 '14 at 09:45

1

$stmt = $db->prepare("SELECT * FROM user WHERE name='Steve Job'");
$stmt->execute();
$stmt->store_result();
$numRows = $stmt->num_rows;
if($numRows > 0){
    echo "1";
}

You need to use store_result before working with num_rows

answered Feb 17 '14 at 09:45

Andy Holmes

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Check if user exist with mysqli doesn't work

1 Answers1