MySQL查询在一个查询中检查多个记录

Question

I have the following data in php:

ID & Timestamps for each blog

Then I have a table which contains:

| id | blog | timestamp |

I need to find out which of my php timestamp data does not equal the timestamp in the mysql database.

Sure I could run a hundred queries for each and every timestamp I have in php to look if it is changed, but that seems inefficient.

Is there any way to put a single query in Mysql to get the data?

To clarify, my php ID & timestamps are in an array like

Array ( [3] => Array ( [timestamp] => 1389414084 ) ) 

I need to check in mysql if the record with ID=3 has the timestamp of 1389414084.

Problem is, with a lot of data to check this would end up being a huge number of queries. And I only need the ones that do not match.

I have no idea how to go about this so any help would be very appreciated.

To clarify - the first data is json. That's how it has to be. I decode it and then have to match it up to the blogs timestamp.

Answer 1

What I would suggest is make hash of ID, Blog & Timestamp and store it in the table itself. And instead of checking id & timestamp, you may check for the hash match (select * from my BlogTimeStamp where hash NOT IN ('hash1', 'hash2', ....).

I don't know your exact requirement. maybe there would be a better solution altogether

Answer 2

SELECT * 
FROM myBlogTable
WHERE timestamp NOT IN (1389414084);

If you use a select statement to get the 1389414084 then insert that in the parentheses instead of hard coding in the timestamp so that the query is dynamic if you ever need it to be.

Answer 3

Here's what I did in the end. I just broke down the query and constructed it so that I had everything in one query.

SELECT * FROM title WHERE id IN((SELECT id FROM title WHERE id = '75' AND date ='1392501995'),(SELECT id FROM title WHERE id = '74' AND date ='1392401481')) 

So you just create it in php.

$i = count($fav);
$sql = 'SELECT * FROM title WHERE id IN(';
    foreach($fav as $key => $val){
        $sql .= "(SELECT id FROM title WHERE id = '".$key."' AND date ='".$val["date"]."')"; 
        if($i > 1) {
            $sql .= ",";
            }
        $i = $i-1;
    }
    $sql .= ")";