从多个表中选择并左联接到一个表

Question

Anybody can help me in solving this problem??

When im joining only 2 tables. It work fine.

but when im trying to select from multiple table. its not working. This is the example of not working code

SELECT ca.cdate as tarikh, sum(transaction.amount) as totalamount 
FROM agent ag, town tw, calendar ca 
LEFT JOIN transaction ON ca.cdate =  DATE_FORMAT(transaction.created_at, '%Y-%m-%d') 
WHERE ca.cdate >= '2014-06-01' AND ca.cdate <= '2014-06-11' 
AND transaction.agent_id = ag.id 
AND ag.town_id = tw.id 
AND tw.state_id = 7;

the result is

After add the group by

SELECT ca.cdate as tarikh, sum(transaction.amount) as totalamount 
FROM agent ag, town tw, calendar ca 
LEFT JOIN transaction ON ca.cdate =  DATE_FORMAT(transaction.created_at, '%Y-%m-%d') 
WHERE ca.cdate >= '2014-06-01' AND ca.cdate <= '2014-06-11' 
AND transaction.agent_id = ag.id 
AND ag.town_id = tw.id 
AND tw.state_id = 7
GROUP BY
ca.cdate;

Trying query suggest by Ambrish

SELECT ca.cdate as tarikh, sum(transaction.amount) as totalamount 
FROM calendar ca 
LEFT JOIN transaction ON ca.cdate = DATE_FORMAT(transaction.created_at, '%Y-%m-%d') 
LEFT JOIN agent ag on transaction.agent_id = ag.id 
LEFT JOIN town tw on ag.town_id = tw.id 
WHERE ca.cdate >= '2014-06-01' 
AND ca.cdate <= '2014-06-11'
AND tw.state_id = 7;

The result is

the 2nd by Ambrish

SELECT ca.cdate as tarikh, sum(transaction.amount) as totalamount 
FROM calendar ca 
LEFT JOIN transaction ON ca.cdate =  DATE_FORMAT(transaction.created_at, '%Y-%m-%d') 
LEFT JOIN agent ag on transaction.agent_id = ag.id
LEFT JOIN town tw on ag.town_id = tw.id 
WHERE ca.cdate >= '2014-06-01' AND ca.cdate <= '2014-06-11' 
AND tw.state_id = 7
group by ca.cdate;

the result is

Answer 1

SELECT ca.cdate as tarikh, sum(transaction.amount) as totalamount 
FROM calendar ca 
LEFT JOIN transaction ON ca.cdate =  DATE_FORMAT(transaction.created_at, '%Y-%m-%d') 
LEFT JOIN agent ag on transaction.agent_id = ag.id
LEFT JOIN town tw ag.town_id = tw.id 
WHERE ca.cdate >= '2014-06-01' AND ca.cdate <= '2014-06-11' 
AND tw.state_id = 7
group by ca.cdate;

If no results are returned then it could be possible that there are no matching records. So, try the query without (or subset of) WHERE clause. Or the query with different values.

Answer 2

SELECT
calendar.cdate,
sum(transaction.amount)
FROM
calendar
LEFT JOIN
(
    select transaction.amount, transaction.created_at from transaction, agent, town
    where
    transaction.agent_id = agent.id
    and agent.town_id = town.id
    and town.state_id = 14
)
transaction
ON calendar.cdate = DATE_FORMAT(transaction.created_at, "%Y-%m-%d") 
WHERE
calendar.cdate >= '2014-06-01' and calendar.cdate <= '2014-06-11'
GROUP BY
calendar.cdate;

Finally i manage to find the answer by using sub query..Thank you for your help..