Question: I have a database with an email field, and it cycles through the database to grab all the transactions concerning a certain email address.

Users putting in lowercase letters when their email is stored with a couple capitals is causing it not to show their transactions. When I modify it to match perfect case with the other emails, it works.

How can I modify this so that it correctly compares with the email field and case doesn't matter? Is it going to be in changing how the email gets stored?

```
$result = mysql_query("SELECT * FROM `example_orders` WHERE `buyer_email`='$useremail';") or die(mysql_error());

```

Thanks ahead of time!

Answer: 
A mixed PHP/MySQL solution:

```
$result = mysql_query("
    SELECT * 
    FROM example_orders
    WHERE LOWER(buyer_email) = '" . strtolower($useremail) . "';
") or die(mysql_error());

```

What it does is converting both sides of the comparison to lowercase. This is not very efficient, because the use of `LOWER` will prevent MySQL from using indexes for searching. 

**A more efficient, pure SQL solution:**

```
$result = mysql_query("
    SELECT * 
    FROM example_orders
    WHERE buyer_email = '$useremail' COLLATE utf8_general_ci;
") or die(mysql_error());

```

In this case, we are forcing the use of a case-insensitive collation for the comparison. You wouldn't need that if the column had a case-insensitive collation in the first place.

Here is how to change the column collation, as suggested by Basti in a comment:

```
ALTER TABLE `example_orders` 
CHANGE `buyer_email` `buyer_email` VARCHAR( 100 ) 
   CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL

```

If you choose to do that, you can run the query without `COLLATE utf8_general_ci`.
Uh... you realize that email addresses are case *sensitive*, right? From [RFC 2821](https://www.ietf.org/rfc/rfc2821.txt):

> 
> Verbs and argument values (e.g., "TO:" or "to:" in the RCPT command  
> 
>  and extension name keywords) are not case sensitive, with the sole  
> 
>  exception in this specification of a mailbox local-part (SMTP  
> 
>  Extensions may explicitly specify case-sensitive elements). That is, 
>  a command verb, an argument value other than a mailbox local-part,  
> 
>  and free form text MAY be encoded in upper case, lower case, or any  
> 
>  mixture of upper and lower case with no impact on its meaning. This  
> 
>  is NOT true of a mailbox local-part. *The local-part of a mailbox  
> 
>  MUST BE treated as case sensitive.* Therefore, SMTP implementations  
> 
>  MUST take care to preserve the case of mailbox local-parts. Mailbox  
> 
>  domains are not case sensitive. In particular, for some hosts the  
> 
>  user "smith" is different from the user "Smith". However, exploiting 
>  the case sensitivity of mailbox local-parts impedes interoperability  
> 
>  and is discouraged.
> 
> 
> 

(emphasis added)