What is the purpose of using COALESCE or IFNULL in PHP?

When retrieving data from a database, there may be cases where the result is NULL. To handle this situation and prevent errors, we can use COALESCE or IFNULL functions in PHP to provide a default value if the result is NULL. This ensures that our code can handle NULL values gracefully and continue to function properly. 

// Example using COALESCE
$query = "SELECT COALESCE(column_name, 'default_value') FROM table_name";
$result = mysqli_query($connection, $query);
$row = mysqli_fetch_assoc($result);
$value = $row['column_name'] ?? 'default_value';

// Example using IFNULL
$query = "SELECT IFNULL(column_name, 'default_value') FROM table_name";
$result = mysqli_query($connection, $query);
$row = mysqli_fetch_assoc($result);
$value = $row['column_name'] ?? 'default_value';

Keywords

COALESCE IFNULL PHP error handling null values

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