如何一次性获取所有选定的ID？ PHP / MySQL问题

Question

I have MySQL table called Files which has file_id column and file_type column (and also other columns that are not relevant to the question).

I would like to get all file_ids of all picture files (i.e. file_type='picture').

I do the query like this:

$pictures_query = mysql_query("SELECT file_id FROM Files WHERE file_type='picture')

and now the question is: how would I put all picture file_ids into an array ?

I thought to do this like that:

$pictures_ids = array();

while ($row = mysql_fetch_row($pictures_query)) {
    $pictures_ids[] = $row[0];
}

Does the loop really necessary, or there is a better way to do this ?

Answer 1

You can use GROUP_CONCAT with explode to avoid looping:

$pictures_query = mysql_query("SELECT GROUP_CONCAT(file_id) FROM Files WHERE file_type='picture'");

$file_ids = explode(',', mysql_result($pictures_query, 0));