mysql将具有相同列值的两行连接起来，并计算某些列值，并在一行中返回所有行

Question

I have a table name agents_commission have columns id, agent_id, deal_id, commission, deal_date.

I want to select agent_id , commission from agents_commission where month( date_deal ) = '$month' and year( date_deal ) ='$year';

but if the table have some rows have the same agent_id join the same rows in one row and calculate the commission values like row 66666.7 + 100000 as in row 1, 2

to be the final fetch_assoc as

array('agent_id'=>1, 'commision'=>166666.7);

thanks

Answer 1

Try using group by and aggregation:

select agentid, sum(commission) as commission
from agents_commission
where month(date_deal) = '$month' and year(date_deal) ='$year';
group by agentid

Answer 2

You can not select all when you want to group by only one column(agentid). you can do something like below

select agent_id, sum(commission) as commission from temp where MONTH(deal_date) = '09' and year(deal_date) ='2018' group by agent_id;

The SELECT statement used in the GROUP BY clause can only be used contain column names, aggregate functions, constants and expressions.

Refer https://dev.mysql.com/doc/refman/5.5/en/group-by-modifiers.html