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  • mysqli_result::$field_count()

    (PHP 5, PHP 7)

    Get the number of fields in a result

    说明

    面向对象风格
    int $mysqli_result->field_count;
    过程化风格
    mysqli_num_fields(mysqli_result$result): int

    Returns the number of fields from specified result set.

    参数

    $result

    仅以过程化样式:由mysqli_query(),mysqli_store_result()或mysqli_use_result()返回的结果集标识。

    返回值

    The number of fields from a result set.

    范例

    Example #1 面向对象风格

    <?php
    $mysqli = new mysqli("localhost", "my_user", "my_password", "world");
    /* check connection */
    if (mysqli_connect_errno()) {
        printf("Connect failed: %s\n", mysqli_connect_error());
        exit();
    }
    if ($result = $mysqli->query("SELECT * FROM City ORDER BY ID LIMIT 1")) {
        /* determine number of fields in result set */
        $field_cnt = $result->field_count;
        printf("Result set has %d fields.\n", $field_cnt);
        /* close result set */
        $result->close();
    }
    /* close connection */
    $mysqli->close();
    ?>
    

    Example #2 过程化风格

    <?php
    $link = mysqli_connect("localhost", "my_user", "my_password", "world");
    /* check connection */
    if (mysqli_connect_errno()) {
        printf("Connect failed: %s\n", mysqli_connect_error());
        exit();
    }
    if ($result = mysqli_query($link, "SELECT * FROM City ORDER BY ID LIMIT 1")) {
        /* determine number of fields in result set */
        $field_cnt = mysqli_num_fields($result);
        printf("Result set has %d fields.\n", $field_cnt);
        /* close result set */
        mysqli_free_result($result);
    }
    /* close connection */
    mysqli_close($link);
    ?>
    

    以上例程会输出:

    Result set has 5 fields.
    

    参见

    • mysqli_fetch_field() Returns the next field in the result set