+ /**
+ * Retrieve the maximum string length allowed in a given column.
+ * The length may either be specified as a byte length or a character length.
+ *
+ * @since 4.2.1
+ * @access public
+ *
+ * @param string $table Table name.
+ * @param string $column Column name.
+ * @return array|false|WP_Error array( 'length' => (int), 'type' => 'byte' | 'char' )
+ * false if the column has no length (for example, numeric column)
+ * WP_Error object if there was an error.
+ */
+ public function get_col_length( $table, $column ) {
+ $tablekey = strtolower( $table );
+ $columnkey = strtolower( $column );
+
+ // Skip this entirely if this isn't a MySQL database.
+ if ( empty( $this->is_mysql ) ) {
+ return false;
+ }
+
+ if ( empty( $this->col_meta[ $tablekey ] ) ) {
+ // This primes column information for us.
+ $table_charset = $this->get_table_charset( $table );
+ if ( is_wp_error( $table_charset ) ) {
+ return $table_charset;
+ }
+ }
+
+ if ( empty( $this->col_meta[ $tablekey ][ $columnkey ] ) ) {
+ return false;
+ }
+
+ $typeinfo = explode( '(', $this->col_meta[ $tablekey ][ $columnkey ]->Type );
+
+ $type = strtolower( $typeinfo[0] );
+ if ( ! empty( $typeinfo[1] ) ) {
+ $length = trim( $typeinfo[1], ')' );
+ } else {
+ $length = false;
+ }
+
+ switch( $type ) {
+ case 'char':
+ case 'varchar':
+ return array(
+ 'type' => 'char',
+ 'length' => (int) $length,
+ );
+
+ case 'binary':
+ case 'varbinary':
+ return array(
+ 'type' => 'byte',
+ 'length' => (int) $length,
+ );
+
+ case 'tinyblob':
+ case 'tinytext':
+ return array(
+ 'type' => 'byte',
+ 'length' => 255, // 2^8 - 1
+ );
+
+ case 'blob':
+ case 'text':
+ return array(
+ 'type' => 'byte',
+ 'length' => 65535, // 2^16 - 1
+ );
+
+ case 'mediumblob':
+ case 'mediumtext':
+ return array(
+ 'type' => 'byte',
+ 'length' => 16777215, // 2^24 - 1
+ );
+
+ case 'longblob':
+ case 'longtext':
+ return array(
+ 'type' => 'byte',
+ 'length' => 4294967295, // 2^32 - 1
+ );
+
+ default:
+ return false;
+ }
+ }
+