Get number of rows matched by UPDATE query with PH

问题:

The older mysql extension has the CLIENT_FOUND_ROWS connection flag, but I couldn't find any equivalent for mysqli.

I have an update query and want to know how many rows its where clause matched, not how many were actually changed (as indicated by mysqli -> affected_rows).

The only way I've figured out so far is to parse mysqli -> info (which looks something like Rows matched: 40 Changed: 40 Warnings: 0) with a regex. But that seems hacky.

回答1:

it's in the options of mysqli_real_connect.

Also introduced in PDO::MySQL in PHP 5.3.

回答2:

I used the following code:

// Parse the digits from the info string that has the following format:
// Rows matched: 0 Changed: 0 Warnings: 0
preg_match_all('!\d+!', $mysqli->info, $m);
return $m[0][0]; 

回答3:

You could run SELECT COUNT(*) with the same WHERE clause before running the UPDATE. That will give you a count of the number of rows that would be matched.

回答4:

Also SELECT ROW_COUNT() can give the number of rows affected by update query.

回答5:

I did an explode function on the results returned from the info command and then took index[1].

$affected = explode(":", $connection->info); $rowsAffected = $affected[1];