wpdb::get_col_length( string $table, string $column )
Retrieve the maximum string length allowed in a given column.
Description
The length may either be specified as a byte length or a character length.
Parameters
- $table
-
(Required) Table name.
- $column
-
(Required) 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.
Source
File: wp-includes/wp-db.php
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;
}
}
Changelog
Version | Description |
---|---|
WP-4.2.1 | Introduced. |