如何结合两个MySQL查询

Question

I want to combine these two queries with two captain should be equal :

select distinct(captain_name),sum(finaldiscount) as tot,payment_mode 
from   order_master 
where  payment_mode='card' 
group  by captain_name

select distinct(captain_name),sum(finaldiscount) as tot,payment_mode 
from   order_master 
where  payment_mode='cash' 
group  by captain_name

Answer 1

Combine can be a JOIN or an UNION

For JOIN :

Select * 
from
(select distinct(captain_name) capName,sum(finaldiscount) as tot,payment_mode from order_master where payment_mode='card' group by captain_name ) t1
INNER JOIN
(select distinct(captain_name) capName,sum(finaldiscount) as tot,payment_mode from order_master where payment_mode='cash' group by captain_name) t2 on t1.capName = t2.capName

For UNION :

Select * 
    from
    (select distinct(captain_name) capName,sum(finaldiscount) as tot,payment_mode from order_master where payment_mode='card' group by captain_name ) t1
    UNION
    (select distinct(captain_name) capName,sum(finaldiscount) as tot,payment_mode from order_master where payment_mode='cash' group by captain_name) t2 

Answer 2

Try this:

SELECT captain_name, 
       SUM(CASE WHEN payment_mode = 'cash' THEN finaldiscount ELSE 0 END) AS cashTotal, 
       SUM(CASE WHEN payment_mode = 'card' THEN finaldiscount ELSE 0 END) AS cardTotal
FROM order_master 
WHERE payment_mode IN ('cash', 'card') 
GROUP BY captain_name

OR

SELECT captain_name, payment_mode, SUM(finaldiscount) total
FROM order_master 
WHERE payment_mode IN ('cash', 'card') 
GROUP BY captain_name, payment_mode

Answer 3

try this :

SELECT captain_name,
       Sum(finaldiscount) AS tot,
       payment_mode
FROM   order_master
WHERE  payment_mode IN( 'cash', 'card' )
       AND captain_name IN (SELECT captain_name
                            FROM   order_master
                            WHERE  payment_mode IN( 'cash', 'card' )
                            GROUP  BY captain_name
                            HAVING Count(DISTINCT payment_mode) = 2)
GROUP  BY captain_name,payment_mode 

the sub query will return only those captain_name which have both payment_mode ie card and cash . then select rows of those captain_name and group by it by captain_name,payment_mode .

and if you don't want separate rows for card and cash then use this :

SELECT captain_name,SUM(finaldiscount)
FROM   order_master
WHERE  payment_mode IN( 'cash', 'card' )
GROUP  BY captain_name
HAVING Count(DISTINCT payment_mode) = 2

Note : I assumed that two captain should be equal means only those captain which are returned by both queries, should be returned by combined query.