PHP check if MySQL table contains variable

Question

So I am new to php and I am trying to check if a mysql table contains a variable which is set when a user does a search. If the table contains the variable (it's a string) then I want to be able to do different things depending on its existence.

I should also note that I am a novice with php development!

This is what I have so far;

$db = new mysqli('IP', 'username', 'password', 'database');

$result = $db->query("SELECT * FROM tablename WHERE ColumnName =     $searchVar");

if(empty($result)){
    //No result Found
}else{
    //Found result
}

SQL strings, like PHP strings, need to be in quotes. Aside from that issue I don't know what your question or issue is. Oh, and you need to fetch the results.. php.net/manual/en/mysqli-result.fetch-assoc.php — chris85
– chris85, Commented Jul 3, 2015 at 0:37
Do you want the record(s)? Where does $searchVar come from, user input? — chris85
– chris85, Commented Jul 3, 2015 at 0:50
@RohitGupta Yes I can connect to the DB and there's no errors. Error reporting is enabled currently too :) @chris85 I dont want to export the records, no. I would like to just check to see if they are infact there. The $searchVar comes from a users input yes. — md_5
– md_5, Commented Jul 3, 2015 at 0:53

Aaron St. Clair · Accepted Answer · 2015-07-03 00:42:19Z

1

You need to place single quotes around $searchVar in the query.

$result = $db->query("SELECT * FROM tablename WHERE ColumnName = '$searchVar'");

Then, you must fetch the results of the query.

$result = $result->fetch_row();

edited Jul 3, 2015 at 0:42

answered Jul 3, 2015 at 0:39

Aaron St. Clair

4891 gold badge4 silver badges14 bronze badges

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

7 Comments

chris85 Over a year ago

He/she hasn't posed a question yet, how can you have an answer?

md_5 Over a year ago

So if I do that, should the rest of my code work? I will try that now buddy!

Aaron St. Clair Over a year ago

OP stated that they would like to query the DB to see if a record exists. The changes I suggested should allow them to do so.

chris85 Over a year ago

Where did OP state that? So I have been trying to check if a mysql table contains a variable (something which is entered in a search) If OP is looking for a record his/her code wont get that.

Kishor Over a year ago

@md_5 - Just keep in mind that, someone who knows SQL can DELETE your whole table if you use these codes. :) Please read about sanitizing user inputs and sql injections.

|

Community · Accepted Answer · 2017-05-23 12:30:03Z

1

Okay so your current query failed because your SQL string wasn't in quotes. It also could have failed once inputted into quotes if your PHP string had a single quote in it. This is how SQL injections occur, user input should never be passed directly into a SQL query. To separate these tasks there are prepared/parameterized queries.

Here's code I think should work for you but this is untested, based off manuals.

$db = new mysqli('IP', 'username', 'password', 'database');
$stmt = $db->prepare('SELECT * FROM tablename WHERE ColumnName = ?');
$stmt->bind_param('s', $searchVar);
$stmt->execute();
if($stmt->num_rows > 0) {
    echo 'there are results';
} else {
    echo 'there are no results';
}

Link to thread on preventing injections: How can I prevent SQL injection in PHP?

edited May 23, 2017 at 12:30

CommunityBot

11 silver badge

answered Jul 3, 2015 at 1:02

chris85

23.9k7 gold badges36 silver badges51 bronze badges

Collectives™ on Stack Overflow

PHP check if MySQL table contains variable

2 Answers 2

7 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related