What is the best practice for preventing duplicate entries in a MySQL table in PHP?

To prevent duplicate entries in a MySQL table in PHP, one common approach is to set a unique constraint on the column(s) that should not have duplicate values. This will ensure that MySQL will not allow any duplicate entries to be inserted. Another approach is to check for the existence of the entry before inserting it into the table. 

// Assuming $connection is your MySQL database connection

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

if($stmt->rowCount() == 0) {
    // Insert the entry into the table
    $insertQuery = "INSERT INTO your_table (column_name) VALUES (:value)";
    $insertStmt = $connection->prepare($insertQuery);
    $insertStmt->bindParam(':value', $value);
    $insertStmt->execute();
    echo "Entry inserted successfully.";
} else {
    echo "Entry already exists.";
}

Keywords

PHP MySQL duplicate entries prevention unique constraint

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