Php/docs/function.mysql-fetch-field
mysql_fetch_field
(PHP 4, PHP 5)
mysql_fetch_field — Get column information from a result and return as an object
Warning This extension was deprecated in PHP 5.5.0, and it was removed in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:
Description
mysql_fetch_field
( resource $result
[, int $field_offset = 0
] ) : object
Returns an object containing field information. This function can be used to obtain information about fields in the provided query result.
Parameters
result- The result resource that is being evaluated. This result comes from a call to mysql_query().
field_offset- The numerical field offset. If the field offset is not specified, the next field that was not yet retrieved by this function is retrieved. The
field_offsetstarts at0.
Return Values
Returns an object containing field information. The properties of the object are:
- name - column name
- table - name of the table the column belongs to, which is the alias name if one is defined
- max_length - maximum length of the column
- not_null - 1 if the column cannot be
NULL - primary_key - 1 if the column is a primary key
- unique_key - 1 if the column is a unique key
- multiple_key - 1 if the column is a non-unique key
- numeric - 1 if the column is numeric
- blob - 1 if the column is a BLOB
- type - the type of the column
- unsigned - 1 if the column is unsigned
- zerofill - 1 if the column is zero-filled
Examples
Example #1 mysql_fetch_field() example
<?php$conn = mysql_connect('localhost', 'mysql_user', 'mysql_password');if (!$conn) { die('Could not connect: ' . mysql_error());}mysql_select_db('database');$result = mysql_query('select * from table');if (!$result) { die('Query failed: ' . mysql_error());}/* get column metadata */$i = 0;while ($i < mysql_num_fields($result)) { echo "Information for column $i:<br />\n"; $meta = mysql_fetch_field($result, $i); if (!$meta) { echo "No information available<br />\n"; } echo "<pre>blob: $meta->blobmax_length: $meta->max_lengthmultiple_key: $meta->multiple_keyname: $meta->namenot_null: $meta->not_nullnumeric: $meta->numericprimary_key: $meta->primary_keytable: $meta->tabletype: $meta->typeunique_key: $meta->unique_keyunsigned: $meta->unsignedzerofill: $meta->zerofill</pre>"; $i++;}mysql_free_result($result);?>
Notes
Note:
Field names returned by this functionare case-sensitive.
Note:
If field or tablenames are aliased in the SQL query the aliased name will be returned. The original name can be retrieved for instance by using mysqli_result::fetch_field().
