Do Not Duplicate VALUE if already exist on MySQL - php

Question

I've been trying to accomplish this, but as other issues I just can't figured it out. I've been reading around for posibles solutions but non of them goes along with my code, or if they do I can't figure out how or where to use them.
I have a DB where a user sends records. The database consist in few tables containing the Following "Name, Lastname, Phone". If any of this values is duplicate, I would like my code to identify and Ignore the submission of the Form if ALL this VALUES already exist on the DB.
Here is my code:
<?php
$con = mysql_connect("HOST","USER","PASS");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("testdb", $con);
$sql="INSERT INTO people (Name, LastName, Phone)
VALUES
('$_POST[Name]','$_POST[LastName]','$_POST[Phone]')";
if (!mysql_query($sql,$con))
{
die('Error: ' . mysql_error());
}
echo "Record Added";
mysql_close($con);
?>

Answer 1

The mysql_* function are all deprecated now, and should NEVER be used. change your code to do something like the following:
//Set up a PDO connection to MySQL
$host = 'host_name';
$dbname = 'database_name';
$user = 'user_name';
$pass = 'user_pass';
try
{
$DB = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
}
catch(PDOException $e)
{
echo $e->getMessage();
}
//Determine whether the appropriate values have been passed.
if(isset($_POST['Name']))
{
$name = $_POST['Name'];
}
else
{
echo "You must provide a name!";
exit; //This may not be what you want to do here, it's an example action
}
if(isset($_POST['LastName']))
{
$name = $_POST['LastName'];
}
else
{
echo "You must provide a last name!";
exit; //This may not be what you want to do here, it's an example action
}
if(isset($_POST['Phone']))
{
$name = $_POST['Phone'];
}
else
{
echo "You must provide a phone number!";
exit; //This may not be what you want to do here, it's an example action
}
//Set up the query using anonymous values
$sql="INSERT INTO people (Name, LastName, Phone) VALUES ('?','?','?')";
$sth = $DB->prepare($sql);
try
{
//Attempt to execute the insert statement
$sth->execute(array($_POST[Name], $_POST[LastName], $_POST[Phone]));
echo "Record Added";
}
catch(PDOException $e)
{
//If the insert failed, then you can handle the error, and determine
//what further steps need to be taken.
echo "Record Not Added";
}
Here's another question with a similar setting, that may also be useful to you:
https://stackoverflow.com/a/10414922/1507210

Answer 2

search in the table before insert
<?php
$con = mysql_connect("HOST","USER","PASS");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("testdb", $con);
$name = mysql_real_escape_string($_POST[Name]);
$LastName= mysql_real_escape_string($_POST[LastName]);
$Phone= mysql_real_escape_string($_POST[Phone]);
$search_res=mysql_query("SELECT * from people where Name='$Name' OR LastName='$LastName' OR Phone='$Phone'");
if(mysql_num_rows($search_res) < 1){
$sql="INSERT INTO people (Name, LastName, Phone)
VALUES
('$Name','$LastName','$Phone')";
if (!mysql_query($sql,$con))
{
die('Error: ' . mysql_error());
}
echo "Record Added";
}else{
echo "User Already exits";
}
mysql_close($con);
?>

Answer 3

Try this easy solution
$result = mysql_query("SELECT * FROM TABLE WHERE Column = 'value' ");
if( mysql_num_rows($result) < 1) {
mysql_query("INSERT INTO table (column) VALUES ('value') ");
}