wpdb::check_safe_collation() protected WP 4.2.0
Checks if the query is accessing a collation considered safe on the current version of MySQL.
{} It's a method of the class: wpdb{}
No Hooks.
Return
true/false. True if the collation is safe, false if it isn't.
Usage
// protected - for code of main (parent) or child class $result = $this->check_safe_collation( $query );
- $query(string) (required)
- The query to check.
Changelog
Since 4.2.0 | Introduced. |
Code of wpdb::check_safe_collation() wpdb::check safe collation WP 5.6
protected function check_safe_collation( $query ) {
if ( $this->checking_collation ) {
return true;
}
// We don't need to check the collation for queries that don't read data.
$query = ltrim( $query, "\r\n\t (" );
if ( preg_match( '/^(?:SHOW|DESCRIBE|DESC|EXPLAIN|CREATE)\s/i', $query ) ) {
return true;
}
// All-ASCII queries don't need extra checking.
if ( $this->check_ascii( $query ) ) {
return true;
}
$table = $this->get_table_from_query( $query );
if ( ! $table ) {
return false;
}
$this->checking_collation = true;
$collation = $this->get_table_charset( $table );
$this->checking_collation = false;
// Tables with no collation, or latin1 only, don't need extra checking.
if ( false === $collation || 'latin1' === $collation ) {
return true;
}
$table = strtolower( $table );
if ( empty( $this->col_meta[ $table ] ) ) {
return false;
}
// If any of the columns don't have one of these collations, it needs more sanity checking.
foreach ( $this->col_meta[ $table ] as $col ) {
if ( empty( $col->Collation ) ) {
continue;
}
if ( ! in_array( $col->Collation, array( 'utf8_general_ci', 'utf8_bin', 'utf8mb4_general_ci', 'utf8mb4_bin' ), true ) ) {
return false;
}
}
return true;
}