Jump to content

Archived

This topic is now archived and is closed to further replies.

chasdrury

Check for duplicates in mySQL using PHP

Recommended Posts

Hi guys

I have created the following PHP script which works perfectly - sends name, phone and email to a mySQL database.

What I need to do it somewhere put in a command that checks the Database for duplicate email entries - The email sends out discount details for the shop so we only want to send one per email address. Is this possible? How would I go about doing this?

Cheers

Chas

[code]$name=$_POST['requiredname'];
$phone=$_POST['requiredphone'];
$email=$_POST['requiredemail'];
$from = "info@hairkandi.com";
$subject = "Hair Kandi Discount Voucher";

mysql_connect(localhost,$username,$password);
@mysql_select_db($database) or die( "Unable to select database");

$query = "INSERT INTO contacts VALUES ('','$name','$phone','$email')";
mysql_query($query);

    //begin message
    $message = <<<EOF
<html>
  <body bgcolor="#333333">[/code]

Share this post


Link to post
Share on other sites
it's been a long time since I've done any PHP coding so if it doesn't work... sorry.

[code]$check = mysql_query("SELECT email FROM contacts");
$result = mysql_fetch_array($check);

foreach ($result as $i)
{
if ($i == $_POST['requiredemail'])
{
exit("dupe");
}
}[/code]

what this *should* do is select all the "email" fields from "contacts" and store them in a new array.

then the foreach() loops through them one by one and check them against $_POST['requiredemail'].

it's a $i matches $_POST['requiredemail'] it will exit().

you can tidy this up a bit so it could print an error message or something.

Share this post


Link to post
Share on other sites
This query will tell you which email addys are duplicated
[code]
SELECT email, COUNT(*) as adcount
FROM contacts
GROUP BY email
HAVING adcount > 1
[/code]

Once you have got rid of the duplicates, put a unique index on email column to prevent further duplication

Share this post


Link to post
Share on other sites
[quote author=chris9902 link=topic=109942.msg443592#msg443592 date=1159526134]
it's been a long time since I've done any PHP coding so if it doesn't work... sorry.

[code]$check = mysql_query("SELECT email FROM contacts");
$result = mysql_fetch_array($check);

foreach ($result as $i)
{
if ($i == $_POST['requiredemail'])
{
exit("dupe");
}
}[/code]

what this *should* do is select all the "email" fields from "contacts" and store them in a new array.

then the foreach() loops through them one by one and check them against $_POST['requiredemail'].

it's a $i matches $_POST['requiredemail'] it will exit().

you can tidy this up a bit so it could print an error message or something.
[/quote]

Thanks. Where would the code go in my PHP then, just with all the other code?

The database is currently empty - what I want to do is stop duplicates from appearing. Is this how to do it?

Chaz

Share this post


Link to post
Share on other sites
if your DB is empty I would use Barand's example and set unique key in your DB.

if you want to use my code then you should put it somewhere before you send the message or add anything to your DB.

no point error checking afterwards is it  ;)

Share this post


Link to post
Share on other sites
Chris9902,

Afraid that code won't work. It fetches all email address but only checks the first one.

Better to look for the specific email address being entered to see if any there already
[code]<?php
$check = mysql_query("SELECT COUNT(*) FROM contacts WHERE email = '$email' ");
if (mysql_result ($check, 0) > 0) {
    // error - email exists
}
else {
    // insert code can go here
}
?>[/code]

Share this post


Link to post
Share on other sites
Thanks guys. I have inputted this into the insert.php script and it still doesn't work. It lets through any email, whether or not they are in the database. The only difference now is that I have put a unique identifier in the email list in the SQL, so the data isn't written to the database, but the people still get the auto email discount thing, since no error is kicked up.

My PHP is below (I have copied in everything upto the start of the discount email)

[code]<?
$username="xxx";
$password="xxx";
$database="xxx";
$name=$_POST['requiredname'];
$phone=$_POST['requiredphone'];
$email=$_POST['requiredemail'];
$from = "info@hairkandi.com";
$subject = "Hair Kandi Discount Voucher";

mysql_connect(localhost,$username,$password);
@mysql_select_db($database) or die( "Unable to select database");
$check = mysql_query("SELECT COUNT(*) FROM contacts WHERE email = '$email' ");
if (mysql_result ($check, 0) > 0) {
    // error - email exists
}
else {
}

$query = "INSERT INTO contacts VALUES ('','$name','$phone','$email')";
mysql_query($query);

    //begin message
    $message = <<<EOF
<html>
  <body bgcolor="#333333">
<table width="511" border="0" cellpadding="0" cellspacing="0">
  <!--DWLayoutTable-->
  <tr>
    <td width="511" height="113" valign="top"><img src=[/code]

What am i doing wrong!!!??

Chaz

Share this post


Link to post
Share on other sites
[code]
else {
}
[/code]

The processing (if no dupes) needs to be inside the else {}

[code]<?php

if (mysql_result ($check, 0) > 0) {
    // error - email exists
    echo "Email exists in file<br/>";
}
else {
    $query = "INSERT INTO contacts VALUES ('','$name','$phone','$email')";
    mysql_query($query);

        //begin message
        $message = <<<EOF
    <html>
      <body bgcolor="#333333">
    <table width="511" border="0" cellpadding="0" cellspacing="0">
      <!--DWLayoutTable-->
      <tr>
        <td width="511" height="113" valign="top"><img src=
       
        ...
        ...
}


?>
[/code]

Share this post


Link to post
Share on other sites

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.