What are the considerations and best practices for handling the assignment of unique identifiers, such as primary keys, when inserting data into a database in PHP?

When inserting data into a database in PHP, it is important to handle the assignment of unique identifiers, such as primary keys, carefully to avoid conflicts and ensure data integrity. One common approach is to use auto-incrementing primary keys in the database table, which automatically assigns a unique identifier to each new record. Another option is to generate a unique identifier in PHP before inserting the data into the database. This can be achieved using functions like uniqid() or UUID.

// Using auto-increment primary key in the database table
$sql = "INSERT INTO table_name (column1, column2) VALUES ('value1', 'value2')";
$result = mysqli_query($connection, $sql);

// Generating a unique identifier in PHP
$unique_id = uniqid();
$sql = "INSERT INTO table_name (id, column1, column2) VALUES ('$unique_id', 'value1', 'value2')";
$result = mysqli_query($connection, $sql);