Do not retrieve emails from the database if the cell is empty

Question

Do not retrieve emails from the database if the cell is empty

I created a code that retrieves emails from all users and saves them in a text file. However, there are some users who don't have an email because they registered using their phone number. When I try to fetch the emails, it gets dumped into the text file like shown in this screenshot here.

My goal is to only fetch emails if the cell is not empty or null. Can someone assist me in fixing this issue?

$sql = mysql_query("SELECT * FROM user"); 
while($row = mysql_fetch_array($sql)) {
$email = $row['email'];
if($email != "" && $email != NULL) {
    $fp = fopen("emaillist.txt", "a");
    $savestring = "\n$email";
    fwrite($fp, $savestring);
    fclose($fp);
}
}
echo  "DONE ";

php mysql

Answer 1

Answer №1

Modify the SQL query to retrieve all records from the "user" table where the email field is not equal to NULL.

SELECT * FROM user WHERE email IS NOT NULL;

Answer 2

Modify the SQL query to retrieve all records from the "user" table where the email field is not equal to NULL.

SELECT * FROM user WHERE email IS NOT NULL;

Answer 3

Answer №2

Retrieving all records from the user table where email is not empty.

To validate against NULL values, the suitable expressions are:

column IS NULL or column IS NOT NULL.

Answer 4

Retrieving all records from the user table where email is not empty.

To validate against NULL values, the suitable expressions are:

column IS NULL or column IS NOT NULL.

Answer 5

Answer №3

Here's an alternative approach:

$sql_query = mysql_query("SELECT * FROM user  "); 
while($data_row = mysql_fetch_array($sql_query)) {


    if (strlen($data_row['email'] ) > 0){
        $user_email = $data_row['email'];
        $file_pointer = fopen("emaillist.txt", "a");
        $save_string = "\n$user_email";
        fwrite($file_pointer, $save_string);
        fclose($file_pointer);
    }
}
echo  "Process complete ";

Answer 6

Here's an alternative approach:

$sql_query = mysql_query("SELECT * FROM user  "); 
while($data_row = mysql_fetch_array($sql_query)) {


    if (strlen($data_row['email'] ) > 0){
        $user_email = $data_row['email'];
        $file_pointer = fopen("emaillist.txt", "a");
        $save_string = "\n$user_email";
        fwrite($file_pointer, $save_string);
        fclose($file_pointer);
    }
}
echo  "Process complete ";

Do not retrieve emails from the database if the cell is empty

Answer №1

Answer №2

Answer №3

Similar questions

Easy PHP navigation options

Ways to prevent ERR_INSUFFICIENT_RESOURCES when making AJAX requests

Looking for a secure method to run code from external sources?

PHP Error - Noticed a non-existent constant 'x' being used in the code, assumed it to be 'x

Symfony2 - Utilizing an Entity repository to encode data into JSON for efficient AJAX calls

Using AJAX, SQL and PHP to send data to a separate page for processing

Switch Your PHP Script to Use PDO

Troubleshooting a logout issue involving Ajax requests and header redirection

Capture and store components in Laravel using a method other than the primaryKey

loop not functioning properly with file type input

The autoloading of Laravel phpspec is not working

Updating databases with the click of a checkbox

Reorganizing Array from PHP after Decoding Facebook Open Graph

Trying to replace apostrophes using preg_replace() and str_replace() turned into a total nightmare! - Re

Unexpected restarts are occurring in a lengthy PHP script

What is the best way to verify HTML using RSS?

What is the best way to create a link in PHP when a backslash is included in the

I am looking to eliminate the double quotation marks from a JSON file so that I can properly utilize

Building a table using jQuery and adding elements using JavaScript's append method

Data from Ajax calls is only available upon refreshing the page