Daniel Bowett wrote:
> Michael Stassen wrote:
>
>> Daniel Bowett wrote:
>>
>>> Peter Brawley wrote:
>>>
>>>> Dan,
>>>>
>>>> />...Total sales for ever would be a simple GROUP BY query with a
>>>> >sum on the sales - but I cant see how I am going to get this info.
>>>> >Do I need to use nested queries? /
>>>>
>>>> You don't need nested queries. It's a crosstab or pivot table query.
>>>> The trick is to sum into one column per desired year, scope the sums
>>>> on month-to-date, and group by retailer, eg:
>>>>
>>>> SELECT
>>>> r.name,
>>>> SUM(IF(LEFT(month_2,4)='2004',sales, '')) AS '2004 Sales',
>>>> SUM(IF(LEFT(month_2,4)='2005',sales, '')) AS '2005 Sales'
>>>> FROM tbl_retailer AS r
>>>> INNER JOIN tbl_sales AS s USING (retailerid)
>>>> WHERE SUBSTRING(month_2,6,2)<MONTH(NOW())
>>>> GROUP BY r.name;
>>>>
>>>> PB
>>>>
>>>> -----
>>>>
>>>> Daniel Bowett wrote:
>>>>
>>>>> I am unsure how to write this query, can someone help?
>>>>>
>>>>> I have two tables.
>>>>>
>>>>> One has a list of retailers (tbl_retailer):
>>>>>
>>>>> retailerid
>>>>> name
>>>>> postcode
>>>>>
>>>>> e.g.
>>>>>
>>>>> 1 Sprocket Supplies CH23 4PY
>>>>>
>>>>> The other has the sales by month for each retailer:
>>>>>
>>>>> retailerid
>>>>> month_2 sales
>>>>>
>>>>> e.g.
>>>>>
>>>>> 1 2004-01 100
>>>>> 1 2004-02 400
>>>>> 1 2004-03 300
>>>>> 1 2004-04 200
>>>>> 1 2004-05 300
>>>>>
>>>>>
>>>>> What I need is a way to output a list of each retailer with two
>>>>> columns at the end being sales this year to date and the equivalent
>>>>> sales for the previous year.
>>>>>
>>>>> So the columns would be:
>>>>>
>>>>> name this_years_sales_to_date last_years_sales_to_date
>>>>>
>>>>> Total sales for ever would be a simple GROUP BY query with a sum on
>>>>> the sales - but I cant see how I am going to get this info. Do I
>>>>> need to use nested queries?
>>>>>
>>>>> Regards,
>>>>>
>>>>> Dan.
>>>>>
>>>>>
>>>>>
>>>>
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>
>>>>
>>>>
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>
>>>>
>>>>
>>>>
>>>
>>> Thats workign great, the only problem is the WHERE clause means I
>>> only show rows where there is sales info in the database. Sometimes
>>> there will be no sales info in there for a particular retailer -
>>> would it be possible to show zero for these?
>>
>>
>>
>> Yes. Change the INNER JOIN to a LEFT JOIN.
>>
>> Michael
>>
>>
>
> I tried a LEFT JOIN earlier - it still only shows rows where there is
> sales. I think it's because of the WHERE clause.
Sorry, my answer was a bit short. You are right, the WHERE clause is the
problem. Conditions on the right side of a LEFT JOIN need to go in the ON
clause, not the WHERE clause, or it defeats the purpose of the LEFT JOIN. So,
your query would be
SELECT
r.name,
SUM(IF(LEFT(s.month_2,4)='2004',s.sales, '')) AS '2004 Sales',
SUM(IF(LEFT(s.month_2,4)='2005',s.sales, '')) AS '2005 Sales'
FROM tbl_retailer AS r
LEFT JOIN tbl_sales AS s
ON r.retailerid = s.retailerid
AND SUBSTRING(s.month_2,6,2) < MONTH(NOW())
GROUP BY r.name;
Michael
