php - 删除旧的数据库条目

Question

我试图在我的数据库中保留 10 个最近的条目并删除旧的。我试过 DELETE FROM people ORDER BY id DESC LIMIT $excess，但它只是删除了前 10 个条目。

$query = "SELECT * FROM people";
$result = mysqli_query($conn, $query);
$count = mysqli_num_rows($result);
if ($count > 10) {
    $excess = $count - 10;
    $query = "DELETE FROM people WHERE id IN(SELECT id FROM people ORDER BY id DESC LIMIT '$excess')";
    mysqli_query($conn, $query);
}

Answer 1

你可以使用这个:-

DELETE FROM `people`
WHERE id NOT IN (
  SELECT id
  FROM (
    SELECT id
    FROM `people`
    ORDER BY id DESC
    LIMIT 10
  ) 
);

此外，您的查询在逻辑上也不正确，您正在按降序获取记录。即 Latest to older 并且您正在删除最新的记录。请改用 ASC。