MySQL join query with multiple where condition - mysql

Question

I have 3 tables. I need to join those 3 and get 2 fields from each table. And there will be few where conditions. Where condition is for date range. Even if one table has the the result I need to show it along with other table data showing as 0.
I have tried using inner join. But what it does is taking only 1st where condition and if no result in first it will not go for next conditions. My table structures and required output are shown below.
table1
+--------+---------+------------+
| amount | site_id | date |
+--------+---------+------------+
| 10 | 1 | 12/12/2014 |
| 50 | 2 | 10/12/2014 |
| 30 | 3 | 05/11/2014 |
+--------+---------+------------+
table2
+--------+---------+------------+
| amount | site_id | date |
+--------+---------+------------+
| 100 | 1 | 2/11/2014 |
| 40 | 2 | 10/10/2014 |
| 30 | 3 | 05/11/2014 |
+--------+---------+------------+
table3
+--------+---------+------------+
| amount | site_id | date |
+--------+---------+------------+
| 60 | 1 | 12/12/2014 |
| 50 | 3 | 11/12/2014 |
| 70 | 4 | 05/09/2014 |
+--------+---------+------------+
output : total amounts between 01/12/2014 and 31/12/2014
+---------+---------------+---------------+---------------+-------+
| site_id | table1_amount | table2_amount | table3_amount | total |
+---------+---------------+---------------+---------------+-------+
| 1 | 60 | 0 | 60 | 120|
| 3 | 0 | 0 | 50 | 50 |
+---------+---------------+---------------+---------------+-------+
Can anyone suggest a query to get this output?
This is what I have done so far
select sum(table1.amount),sum(table2.amount),sum(table3.amount),(sum(table1.amount)+sum(table2.amount)+sum(table3.amount)) from table1 inner join table2 on table1.site_id=table2.site_id inner join table3 on table3.site_id=table2.site_id where table1.date>='01/12/2014' and table1.date<='31/12/2014' or table2.date>='01/12/2014' and table2.date<='31/12/2014' or table3.date>='01/12/2014' and table3.date<='31/12/2014' group by table1.site_id

Answer 1

Try this:
SELECT S.site_id,
IFNULL(t1.table1_Amount, 0) AS table1_Amount,
IFNULL(t2.table2_Amount, 0) AS table2_Amount,
IFNULL(t3.table3_Amount, 0) AS table3_Amount,
(IFNULL(t1.table1_Amount, 0) + IFNULL(t2.table2_Amount, 0) + IFNULL(t3.table3_Amount, 0)) AS total
FROM Site S
LEFT OUTER JOIN ( SELECT t1.site_id, SUM(t1.amount) AS table1_Amount
FROM table1 t1
WHERE t1.date >= '01/12/2014' AND t1.date <= '31/12/2014'
GROUP BY t1.site_id
) AS t1 ON S.site_id = t1.site_id
LEFT OUTER JOIN ( SELECT t2.site_id, SUM(t2.amount) AS table2_Amount
FROM table2 t2
WHERE t2.date >= '01/12/2014' AND t2.date <= '31/12/2014'
GROUP BY t2.site_id
) AS t2 ON S.site_id = t2.site_id
LEFT OUTER JOIN ( SELECT t3.site_id, SUM(t3.amount) AS table3_Amount
FROM table1 t3
WHERE t3.date >= '01/12/2014' AND t3.date <= '31/12/2014'
GROUP BY t3.site_id
) AS t3 ON S.site_id = t3.site_id;