使用 MySQLi 的 SUM 的单个结果

Question

Looked all over. Can't find an answer. PHP docs not clear (to me).

I'm doing a simple MySQL sum through mysqli->query . How can I get the result with MySQLi like mysql_result ?

Answer 1

It's best if you used an alias for your SUM:

SELECT SUM(`field`) as `sum` FROM `table_name`

And then, you'll be able to fetch the result normally by accessing the first result row's $row['sum'] .

Answer 2

Whatever is given in the SELECT statement to mysqli_query is going to return a mysql_result type if the query was successful. So if you have a SELECT statement such as:

SELECT sum(field) FROM table1

you still need to fetch the row with the result, and the value of the sum() function will be the only entry in the row array:

$res = mysqli_query($dbh,'SELECT sum(field) FROM table1');
$row = mysqli_fetch_row($res);
$sum = $row[0];