mysqli_stmt::result_metadata
, mysqli_stmt_result_metadata
mysqli_stmt::result_metadata
mysqli_stmt_result_metadata
Returns result set metadata from a prepared statement
Description
Object oriented stylemysqli_result mysqli_stmt::result_metadata();
Procedural stylemysqli_result mysqli_stmt_result_metadata(mysqli_stmt stmt);
If a statement passed to mysqli_prepare
is one that produces a result set, mysqli_stmt_result_metadata
returns the result object that can be used to process the meta information such as total number of fields and individual field information.Note
This result set pointer can be passed as an argument to any of the field-based functions that process result set metadata, such as:
mysqli_num_fields
mysqli_fetch_field
mysqli_fetch_field_direct
mysqli_fetch_fields
mysqli_field_count
mysqli_field_seek
mysqli_field_tell
mysqli_free_result
The result set structure should be freed when you are done with it, which you can do by passing it to mysqli_free_result
Note
The result set returned by mysqli_stmt_result_metadata
contains only metadata. It does not contain any row results. The rows are obtained by using the statement handle with mysqli_stmt_fetch
.
Parameters
stmt
-
Procedural style only: A statement identifier returned by
mysqli_stmt_init
.
Return Values
Returns a result object or FALSE
if an error occurred.
Examples
Example 20.168. Object oriented style
<?php $mysqli = new mysqli('localhost', 'my_user', 'my_password', 'test'); $mysqli->query('DROP TABLE IF EXISTS friends'); $mysqli->query('CREATE TABLE friends (id int, name varchar(20))'); $mysqli->query('INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')'); $stmt = $mysqli->prepare('SELECT id, name FROM friends'); $stmt->execute(); /* get resultset for metadata */ $result = $stmt->result_metadata(); /* retrieve field information from metadata result set */ $field = $result->fetch_field(); printf('Fieldname: %s\n', $field->name); /* close resultset */ $result->close(); /* close connection */ $mysqli->close(); ?>
Example 20.169. Procedural style
<?php $link = mysqli_connect('localhost', 'my_user', 'my_password', 'test'); mysqli_query($link, 'DROP TABLE IF EXISTS friends'); mysqli_query($link, 'CREATE TABLE friends (id int, name varchar(20))'); mysqli_query($link, 'INSERT INTO friends VALUES (1,'Hartmut'), (2, 'Ulf')'); $stmt = mysqli_prepare($link, 'SELECT id, name FROM friends'); mysqli_stmt_execute($stmt); /* get resultset for metadata */ $result = mysqli_stmt_result_metadata($stmt); /* retrieve field information from metadata result set */ $field = mysqli_fetch_field($result); printf('Fieldname: %s\n', $field->name); /* close resultset */ mysqli_free_result($result); /* close connection */ mysqli_close($link); ?>
See Also
mysqli_prepare
|
mysqli_free_result |