result-metadata

mysqli_stmt::result_metadata

mysqli_stmt_result_metadata

Returns result set metadata from a prepared statement

ENTITY

ENTITY

ENTITY

mysqli_result

false

mysqli_stmt_result_metadata

mysqli_stmt

statement

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.

This function returns an empty mysqli_result object which can be used to access metadata information from the prepared statement without having to fetch the actual rows of data. There is no need to use this function when using mysqli_stmt_get_result to retrieve the entire result set from a prepared statement as a result object.

[!NOTE] This result set object can be passed as an argument only to 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

[!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 calling mysqli_stmt_get_result on the statement handle or with mysqli_stmt_fetch.

ENTITY

ENTITY

Returns a result object or ENTITY if an error occurred. If the statement does not produce a result set, ENTITY is returned as well.

ENTITY ENTITY

ENTITY

<?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);
?>

   

<?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);
?>

   

ENTITY

mysqli_prepare, mysqli_free_result, mysqli_stmt_get_result