如何使用mysqli_fetch_all（）从查询中返回空数组或结果集？

Question

My PHP code:

function get_something() {

  global $link;

  $sql = "SELECT * FROM new";

  $result = mysqli_query($link, $sql);

  $names = mysqli_fetch_all($result, MYSQLI_ASSOC);

  return $names;

}

What is my problem:

When my table new is empty, I get the following error:

mysqli_fetch_all() expects parameter 1 to be mysqli_result`

If it isn't empty everything is working fine.

I need to check if my database is empty and if it's not, I will call mysqli_fetch_all. Otherwise, my function should return an empty array.

How is this possible to do?

Answer 1

Use mysqli_num_rows($result) to check how many rows were returned from the query. But if table new doesn't exist, $result will be false so we have to check that $result is valid as well:

if ($result && mysqli_num_rows($result) > 0)
    $names = mysqli_fetch_all($result, MYSQLI_ASSOC);
else
    $names = array();
return $names;