I have two SQL Tables in my database
Structure of table1 is ie customer_classification
is
CREATE TABLE IF NOT EXISTS `customer_classification` ( `sid` int(5) NOT NULL, `customer_id` varchar(15) NOT NULL, `classification` varchar(5) NOT NULL, `appendix_id` int(5) NOT NULL, `bill_date` date NOT NULL );
Structure of table2 is ie customer_consumption
is
CREATE TABLE IF NOT EXISTS `customer_consumption` `sid` int(5) NOT NULL, `customer_id` varchar(25) NOT NULL, `bill_date` date NOT NULL, `reading` float NOT NULL, `consumption` float NOT NULL, `energy_bill` float NOT NULL, `meter_rent` float NOT NULL, `arrear` float NOT NULL );
In both tables, primary keys are customer_id
and bill_date
, because in a particular month there is only bill corresponding to single customer.
Now, my problem is, I am not able to merge these tables data into one to display the whole record.
I have tried this Sql Query, have a look
select co.customer_id, co.reading, co.consumption, cl.classification
from customer_consumption as co
INNER JOIN customer_classification as cl
on cl.customer_id = co.customer_id
and month(cl.bill_date) = month(co.bill_date)
where month(co.bill_date) = month(now())
It is not giving me the accurate result
I am going to guess that the consumption table has records for each month and the classification record only has records when the classification changes. If so, you want to get the most recent classification. And you can do that as:
select co.customer_id, co.reading, co.consumption,
(select cl.classification
from customer_classification as cl
where cl.customer_id = co.customer_id and
cl.bill_date <= co.bill_date
order by cl.bill_date desc
limit 1
) as classification
from customer_consumption co
where month(co.bill_date) = month(now());
Try this SQL query
select co.customer_id, sum(co.reading), sum(co.consumption), cl.classification
from customer_consumption as co
INNER JOIN customer_classification as cl
on cl.customer_id = co.customer_id
and month(cl.bill_date) = month(co.bill_date)
where month(co.bill_date) = month(now())
group by co.customer_id
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