mysqli_stmt::data_seek()

(PHP 5, PHP 7)

Seeks to an arbitrary row in statement result set

说明

面向对象风格
mysqli_stmt::data_seek(int $offset): void

过程化风格
mysqli_stmt_data_seek(mysqli_stmt$stmt,int $offset): void

Seeks to an arbitrary result pointer in the statement result set.

mysqli_stmt_store_result() must be called prior to mysqli_stmt_data_seek().

参数

$stmt

仅以过程化样式：由mysqli_stmt_init()返回的 statement 标识。

$offset

Must be between zero and the total number of rows minus one(0..mysqli_stmt_num_rows() 1).

返回值

没有返回值。

范例

Example #1 面向对象风格

<?php
/* Open a connection */
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
$query = "SELECT Name, CountryCode FROM City ORDER BY Name";
if ($stmt = $mysqli->prepare($query)) {
    /* execute query */
    $stmt->execute();
    /* bind result variables */
    $stmt->bind_result($name, $code);
    /* store result */
    $stmt->store_result();
    /* seek to row no. 400 */
    $stmt->data_seek(399);
    /* fetch values */
    $stmt->fetch();
    printf ("City: %s  Countrycode: %s\n", $name, $code);
    /* close statement */
    $stmt->close();
}
/* close connection */
$mysqli->close();
?>

Example #2 过程化风格

<?php
/* Open a connection */
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
$query = "SELECT Name, CountryCode FROM City ORDER BY Name";
if ($stmt = mysqli_prepare($link, $query)) {
    /* execute query */
    mysqli_stmt_execute($stmt);
    /* bind result variables */
    mysqli_stmt_bind_result($stmt, $name, $code);
    /* store result */
    mysqli_stmt_store_result($stmt);
    /* seek to row no. 400 */
    mysqli_stmt_data_seek($stmt, 399);
    /* fetch values */
    mysqli_stmt_fetch($stmt);
    printf ("City: %s  Countrycode: %s\n", $name, $code);
    /* close statement */
    mysqli_stmt_close($stmt);
}
/* close connection */
mysqli_close($link);
?>

以上例程会输出：

City: Benin City  Countrycode: NGA

参见

• mysqli_prepare() 准备执行一个 SQL 语句

Although the documentation says you must provide a number between 0 and count - 1, you can actually supply a negative number, which appears to be cast to positive (such as in abs()).
For example:
<?php
$db = new mysqli('localhost', 'test', 'password', 'schema');
$db->multi_query("
      SELECT * FROM
      (
        SELECT 1 as 'position'
        UNION SELECT 2 as 'position'
        UNION SELECT 3 as 'position'
        UNION SELECT 4 as 'position'
        UNION SELECT 5 as 'position'
      ) as rows");
      
$result = $db->store_result();
for ($i = 0; $i < $result->num_rows; $i++)
{
  $offset = $i;
  $result->data_seek($offset);
  var_dump("Seek offset is: {$offset}", $result->fetch_object());
}
for ($i = 0; $i < $result->num_rows; $i++)
{
  $offset = -$i;
  $result->data_seek($offset);
  var_dump("Seek offset is: {$offset}", $result->fetch_object());
}