mysql_fetch_field

(PHP 3, PHP 4 >= 4.0.0)

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_select_db("database");
$result = mysql_query("select * from table")
 or die("Query failed");
# 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().