How can the database itself be utilized to determine if an entry already exists before inserting a new entry in PHP?

To determine if an entry already exists before inserting a new entry in PHP, you can query the database to check if a record with the same data already exists. This can be done using a SELECT query to retrieve the existing record based on certain criteria, such as a unique identifier. If a record is returned, it means the entry already exists and you can choose to update it instead of inserting a new one.

// Assume $connection is the database connection object

// Check if the entry already exists
$query = "SELECT * FROM table_name WHERE unique_field = :value";
$stmt = $connection->prepare($query);
$stmt->bindParam(':value', $value);
$stmt->execute();

if($stmt->rowCount() > 0){
    // Entry already exists, update the record
    // Perform an UPDATE query here
} else {
    // Entry does not exist, insert a new record
    // Perform an INSERT query here
}