mysql_fetch_field

Get column information from a result and return as an object (PHP 3, PHP 4 )
object mysql_fetch_field ( resource result [, int field_offset ] )

Returns an object containing field information.

mysql_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retrieved by mysql_fetch_field() is retrieved.

The properties of the object are:

  • name - column name
  • table - name of the table the column belongs to
  • 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
Note:

Field names returned by this function are case-sensitive.

Example 599. mysql_fetch_field() example

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<?php
mysql_connect('localhost:3306', $user, $password)
   or die("Could not connect: " . mysql_error());
mysql_select_db("database");
$result = mysql_query("select * from table")
   or die("Query failed: " . mysql_error());
/* get column metadata */
$i = 0;
while ($i < mysql_num_fields($result)) {
   echo "Information for column $i:<br />\n";
   $meta = mysql_fetch_field($result);
   if (!$meta) {
       echo "No information available<br />\n";
   }
   echo "<pre>
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
unique_key:   $meta->unique_key
unsigned:     $meta->unsigned
zerofill:     $meta->zerofill
</pre>";
   $i++;
}
mysql_free_result($result);
?>

See also mysql_field_seek().

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