PHP/MySQL Verify Value Exists In Column

Question

I'm using PHP/MySQL to verify that one value exists in the column "tokencol". "$token" is the value that I want to verify and I'm sure that it has been entered properly.

Below is my code:

$verifytoken = mysql_query("SELECT * from tokens where tokenrow = '$token'");


if(mysql_num_rows($verifytoken) == TRUE) {
     echo "hello";
} else {
    die("Valid token not provided.");
}

I always get the "Valid token not provided." message instead of "hello".

What should I do to fix? Thanks

var_dump or print_r result of query $verifytoken and also check what mysql_error says. — Bartosz Polak
– Bartosz Polak, Commented Feb 18, 2014 at 8:10

Community · Accepted Answer · 2023-11-17 19:52:31Z

3

mysql_num_rows() returns a integer value and not Boolean value.so what you was trying is basically wrong. So try comparing with int values like this

if(mysql_num_rows($verifytoken) != 0) {
     echo "hello";
} else {
    die("Valid token not provided.");
}

also mysql_* functions are deprecated from php5.5. so try to stop using it and start using mysqli_* functions or PDO

edited Nov 17, 2023 at 19:52

CommunityBot

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answered Feb 18, 2014 at 8:12

krishna

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4 Comments

krishna Over a year ago

no. if it is == 0 means not found and != 0 means found. because it returns no of rows the query returns

user2248259 Over a year ago

Weird...It's now showing that the value is not found.

user2248259 Over a year ago

$dbconnect = mysql_connect('mysqlhost', 'mysql-user', 'mysql-password', 'mysql-db'); Does it look right?

krishna Over a year ago

the dbconnect was correct.Make sure that you have a row in database having $token value as tokenrow value

cornelb · Accepted Answer · 2014-02-18 08:54:23Z

2

Are you sure the database connection is ok and you have that value in the tokens table?

Try with $verifytoken = mysql_query("SELECT * from tokens where tokenrow = '$token'") or die(mysql_error());

edited Feb 18, 2014 at 8:54

answered Feb 18, 2014 at 8:07

cornelb

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Comments

Pavel Štěrba · Accepted Answer · 2014-02-18 08:08:12Z

0

It's better do it like this, if you need only amount of toknes:

$verifytoken = mysql_query("SELECT COUNT(*) from tokens where tokenrow = '$token'");

if(mysql_result($verifytoken, 0) > 0) {
     echo "hello";
} else {
    die("Valid token not provided.");
}

With mysql_num_rows mysql has to prepare structure for returned data and then count the result. With COUNT it will directly return just amount. Also, if you have for example some tokenid column in your table, do it like SELECT COUNT(tokenid)....

answered Feb 18, 2014 at 8:08

Pavel Štěrba

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Comments

Ashley Medway · Accepted Answer · 2014-02-18 08:30:16Z

0

$verifytoken = mysql_query("SELECT * from tokens where tokenrow = '$token'");
if($row_verifytoken = mysql_fetch_assoc($verifytoken))
{
    echo "hello"; 
}
else 
{
    die("Valid token not provided.");
}

edited Feb 18, 2014 at 8:30

Ashley Medway

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answered Feb 18, 2014 at 8:10

wild

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