What are the best practices for structuring database tables in PHP applications to avoid duplicate entries?

To avoid duplicate entries in database tables in PHP applications, it is important to properly structure the tables with unique constraints on relevant columns. This can prevent the insertion of duplicate records and ensure data integrity. Additionally, implementing validation checks in the application logic before inserting data can help identify and prevent duplicate entries. 

// Example of creating a table with a unique constraint in PHP using PDO
try {
    $pdo = new PDO("mysql:host=localhost;dbname=mydatabase", "username", "password");
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $pdo->exec("CREATE TABLE IF NOT EXISTS users (
        id INT AUTO_INCREMENT PRIMARY KEY,
        username VARCHAR(50) UNIQUE,
        email VARCHAR(100) UNIQUE
    )");
} catch(PDOException $e) {
    echo "Error creating table: " . $e->getMessage();
}

Keywords

database tables PHP applications duplicate entries structuring best practices

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