Foxpro complex sub query - mysql

Question

I'm having a hard time doing a query in foxpro 2.6 (no other choice)
note from some reason union queries do not work.
stockw (item, qte, dat) item is key
shist (item, qte, date) each row is a purchase for item and qte and date
the below query will calculate the first purchase for an item in shist to know how many months we've been selling every item since the beginning of the year
select shist.item as s_item, MIN(shist.date),stockw.qte as qte_remain,;
IIF( YEAR(MIN(shist.date)) < 2013, MONTH(DATE()), MONTH(DATE())-MONTH(shist.date)+1 ) as months;
FROM shist,stockw;
WHERE (shist.item LIKE 'LF-TK%' OR shist.item LIKE 'PL%' OR shist.item LIKE 'LF-A%') AND stockw.item = shist.item;
GROUP BY shist.item;
into CURSOR x
i want to:
- calculate the average qte from the beginning of the year 2013 till now for each item SUM(shist.qte)/months (months is calculated from the above query for each item)
maybe in a different query i want the below:
- select the max of sum of shist.qte for every month for each item (get highest month) from the beginning of the year 2013 till now.

Answer 1

Since I'm not quite following where you would be applying a union, and appears you have multiple times you are running the query, here is a VERY OLD trick that was usable in the old days of VFP...
When you do a select into cursor, the cursor is typically read-only and not read-write to append to... BUT, if you use the result of the first time run query AGAIN as a different alias, you CAN append to it. Something along the lines of...
use in select( "C_ThisIsMaster" )
for i = 1 to 10
use in select( "C_ThisRun" )
select blah, blah2, blah3 ;
from YourTables;
where SomeKey = SomeIDForCyclei;
into cursor C_ThisRun
if not used( "C_ThisIsMaster" )
select 0
use ( dbf( "C_ThisRun") ) again alias C_ThisIsMaster
else
select C_ThisIsMaster
append from dbf( "C_ThisRun" )
endif
endfor
The for[i] loop is just a sample, but if you are running for many cycles that you would do the UNION for, you can just pull that into a query and simulate the same, such as via
select *
from SomeTable
where SomeCondition
into cursor C_DoTheseItems
use in select( "C_ThisIsMaster" )
select C_DoTheseItems
do while not eof()
Do the same thing as inside the FOR loop above
select C_DoTheseItems
skip
enddo
I know VFP has scan/endscan, but don't remember how far back that originated, so using the do while NOT eof() was used here...
At the end of either option would give you a simulated UNION of each item you were trying to process into one "alias" result "C_ThisIsMaster" to work with