mysql_fetch_field

Description

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

<?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().