mysqli_result::fetch_field

mysqli_fetch_field

(PHP 5, PHP 7, PHP 8)

mysqli_result::fetch_field -- mysqli_fetch_field — Returns the next field in the result set

Опис

Об'єктно-орієнтований стиль

public mysqli_result::fetch_field(): object|false

Процедурний стиль

mysqli_fetch_field(mysqli_result $result): object|false

Returns the definition of one column of a result set as an object. Call this function repeatedly to retrieve information about all columns in the result set.

Параметри

result: Тільки процедурний стиль: об'єкт mysqli_result, якого повертає одна з функцій mysqli_query(), mysqli_store_result(), mysqli_use_result() або mysqli_stmt_get_result().

Значення, що повертаються

Returns an object which contains field definition information or false if no field information is available.

**Object properties**
Property	Description
name	The name of the column
orgname	Original column name if an alias was specified
table	The name of the table this field belongs to (if not calculated)
orgtable	Original table name if an alias was specified
def	Unused. Always an empty string
db	The name of the database
catalog	Unused. Always `"def"`
max_length	The maximum width of the field for the result set. As of PHP 8.1, this value is always `0`.
length	The width of the field in bytes. For string columns, the length value varies on the connection character set. For example, if the character set is `latin1`, a single-byte character set, the length value for a `SELECT 'abc'` query is 3. If the character set is `utf8mb4`, a multibyte character set in which characters take up to 4 bytes, the length value is 12.
charsetnr	The character set number for the field.
flags	An integer representing the bit-flags for the field.
type	The data type used for this field
decimals	The number of decimals for numeric fields, and the fractional seconds precision for temporal fields.

Приклади

Приклад #1 Об'єктно-орієнтований стиль

<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$query = "SELECT Name, SurfaceArea from Country ORDER BY Code LIMIT 5";

if ($result = $mysqli->query($query)) {

    /* Get field information for all columns */
    while ($finfo = $result->fetch_field()) {

        printf("Name:     %s\n", $finfo->name);
        printf("Table:    %s\n", $finfo->table);
        printf("max. Len: %d\n", $finfo->max_length);
        printf("Flags:    %d\n", $finfo->flags);
        printf("Type:     %d\n\n", $finfo->type);
    }
    $result->close();
}

/* close connection */
$mysqli->close();
?>

Приклад #2 Процедурний стиль

<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$query = "SELECT Name, SurfaceArea from Country ORDER BY Code LIMIT 5";

if ($result = mysqli_query($link, $query)) {

    /* Get field information for all fields */
    while ($finfo = mysqli_fetch_field($result)) {

        printf("Name:     %s\n", $finfo->name);
        printf("Table:    %s\n", $finfo->table);
        printf("max. Len: %d\n", $finfo->max_length);
        printf("Flags:    %d\n", $finfo->flags);
        printf("Type:     %d\n\n", $finfo->type);
    }
    mysqli_free_result($result);
}

/* close connection */
mysqli_close($link);
?>

Подані вище приклади виведуть:

Name:     Name
Table:    Country
max. Len: 11
Flags:    1
Type:     254

Name:     SurfaceArea
Table:    Country
max. Len: 10
Flags:    32769
Type:     4

Прогляньте також

mysqli_num_fields() - Gets the number of fields in the result set
mysqli_fetch_field_direct() - Fetch meta-data for a single field
mysqli_fetch_fields() - Returns an array of objects representing the fields in a result set
mysqli_field_seek() - Set result pointer to a specified field offset