Forum und email


(PHP 4, PHP 5, PECL mysql:1.0)

mysql_fetch_field — Get column information from a result and return as an object


object mysql_fetch_field ( resource $result [, int $field_offset ] )

Returns an object containing field information. This function can be used to obtain information about fields in the provided query result.



The result resource that is being evaluated. This result comes from a call to mysql_query().


The numerical field offset. If the field offset is not specified, the next field that was not yet retrieved by this function is retrieved. The field_offset starts at 0.

Return values

Returns an object containing field information. The properties of the object are:

  • name - column name
  • table - name of the table the column belongs to
  • def - default value of the column
  • max_length - maximum length of the column
  • not_null - 1 if the column cannot be NULL
  • primary_key - 1 if the column is a primary key
  • unique_key - 1 if the column is a unique key
  • multiple_key - 1 if the column is a non-unique key
  • numeric - 1 if the column is numeric
  • blob - 1 if the column is a BLOB
  • type - the type of the column
  • unsigned - 1 if the column is unsigned
  • zerofill - 1 if the column is zero-filled


Example#1 mysql_fetch_field() example

if (!
$conn) {
'Could not connect: ' mysql_error());
$result mysql_query('select * from table');
if (!
$result) {
'Query failed: ' mysql_error());
/* get column metadata */
$i 0;
while (
$i mysql_num_fields($result)) {
"Information for column $i:<br />\n";
$meta mysql_fetch_field($result$i);
    if (!
$meta) {
"No information available<br />\n";
blob:         $meta->blob
max_length:   $meta->max_length
multiple_key: $meta->multiple_key
name:         $meta->name
not_null:     $meta->not_null
numeric:      $meta->numeric
primary_key:  $meta->primary_key
table:        $meta->table
type:         $meta->type
default:      $meta->def
unique_key:   $meta->unique_key
unsigned:     $meta->unsigned
zerofill:     $meta->zerofill


Note: Field names returned by this function are case-sensitive.