mysqli_stmt::result_metadata

mysqli_stmt_result_metadata

Returns result set metadata from a prepared statement

Description

Object oriented style

mysqli_result mysqli_stmt::result_metadata ( void )

Procedural style

mysqli_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 #1 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 #2 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