Display error message in php for MYSQL duplicate error - php

Question

I am using UNIQUE Constraint in my table for two columns to prevent duplicate rows. If I try to insert a row with the same 2 columns I get
A Database Error Occurred Error
Number: 1062
Duplicate entry '62-88' for key
'subscription'
INSERT INTO subscriptions
(user_id, subscribed_to, date)
VALUES ('62', '88', '2011-07-11
19:15:13')
Filename:
C:\wamp\www\mysite\system\database\DB_driver.php
Line Number: 330
How can I return a php error, e..g Already subscribed! instead of displaying the mysql error?

Answer 1

Call mysql_errno() after your mysql_query() and check for 1062.
Note: It's a more common/intuitive solution to query the database first. See answer by Manocho.

Answer 2

I think you will need to run a query manually to check if the entry already exists in your database. so something like: SELECT COUNT(*) FROM subscriptions WHERE (user_id = '62' AND subscribed_to = '88'). If the count returned is > 0 then return the error, however you want it displayed.

Answer 3

http://php.net/manual/en/function.mysql-error.php I assume you are able to programatically obtain the MySQL error
http://www.php.net/manual/en/function.mysql-errno.php
http://dev.mysql.com/doc/refman/5.5/en/error-handling.html
Using the 3rd link, compare the mysql error or mysql errno to the list of errors and if the condition is met, provide your alternate error message.

Answer 4

To solve the error you can do this:
mysql_query($sql);
if (mysql_errno() == 1062) {
print "<script type=\"text/javascript\">";
print "alert('The informations are already inserted')";
print "</script>";
}

Answer 5

try this code :
$query = "INSERT INTO ".$table_name." ".$insertdata;
if(mysqli_query($conn,$query)){
echo "data inserted into DB<br>";
}else{
if(mysqli_errno($conn) == 1062)
echo "duplicate entry no need to insert into DB<br>";
else
echo "db insertion error:".$query."<br>";
}//else end