wpdb::determine_charset() │ public │ WP 4.6.0

Determines the best charset and collation to use given a charset and collation.

For example, when able, utf8mb4 should be used instead of utf8.

Method of the class: wpdb{}

No Hooks.

Return

Array. The most appropriate character set and collation to use.

Usage

global $wpdb;
$wpdb->determine_charset( $charset, $collate );

$charset(string) (required)

The character set to check.

$collate(string) (required)

The collation to check.

Changelog

wpdb::determine_charset() wpdb::determine charset code ^{WP 6.7.2}

public function determine_charset( $charset, $collate ) {
	if ( ( ! ( $this->dbh instanceof mysqli ) ) || empty( $this->dbh ) ) {
		return compact( 'charset', 'collate' );
	}

	if ( 'utf8' === $charset ) {
		$charset = 'utf8mb4';
	}

	if ( 'utf8mb4' === $charset ) {
		// _general_ is outdated, so we can upgrade it to _unicode_, instead.
		if ( ! $collate || 'utf8_general_ci' === $collate ) {
			$collate = 'utf8mb4_unicode_ci';
		} else {
			$collate = str_replace( 'utf8_', 'utf8mb4_', $collate );
		}
	}

	// _unicode_520_ is a better collation, we should use that when it's available.
	if ( $this->has_cap( 'utf8mb4_520' ) && 'utf8mb4_unicode_ci' === $collate ) {
		$collate = 'utf8mb4_unicode_520_ci';
	}

	return compact( 'charset', 'collate' );
}