How to declare an array inside MS SQL Server Stored Procedure? - sql-server-2008

Question

I need to declare 12 decimal variables, corresponding to each month's year, with a cursor I sum values to this variables, then later I Update some sales information.
I don't know if sql server has this syntax
Declare MonthsSale(1 to 12) as decimal(18,2)
This code works Ok. !
CREATE PROCEDURE [dbo].[proc_test]
AS
BEGIN
--SET NOCOUNT ON;
DECLARE #monthsales TABLE ( monthnr int, amount decimal(18,2) )
-- PUT YOUR OWN CODE HERE
-- THIS IS TEST CODE
-- 1 REPRESENTS JANUARY, ...
INSERT #monthsales (monthnr, amount) VALUES (1, 100)
INSERT #monthsales (monthnr, amount) VALUES (1, 100)
INSERT #monthsales (monthnr, amount) VALUES (2, 200)
INSERT #monthsales (monthnr, amount) VALUES (3, 300)
INSERT #monthsales (monthnr, amount) VALUES (4, 400)
INSERT #monthsales (monthnr, amount) VALUES (5, 500)
INSERT #monthsales (monthnr, amount) VALUES (6, 600)
INSERT #monthsales (monthnr, amount) VALUES (7, 700)
INSERT #monthsales (monthnr, amount) VALUES (8, 800)
INSERT #monthsales (monthnr, amount) VALUES (9, 900)
INSERT #monthsales (monthnr, amount) VALUES (10, 1000)
INSERT #monthsales (monthnr, amount) VALUES (11, 1100)
INSERT #monthsales (monthnr, amount) VALUES (12, 1200)
SELECT monthnr, SUM(amount) AS SUM_MONTH_1 FROM #monthsales WHERE monthnr = 1 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_2 FROM #monthsales WHERE monthnr = 2 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_3 FROM #monthsales WHERE monthnr = 3 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_4 FROM #monthsales WHERE monthnr = 4 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_5 FROM #monthsales WHERE monthnr = 5 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_6 FROM #monthsales WHERE monthnr = 6 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_7 FROM #monthsales WHERE monthnr = 7 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_8 FROM #monthsales WHERE monthnr = 8 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_9 FROM #monthsales WHERE monthnr = 9 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_10 FROM #monthsales WHERE monthnr = 10 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_11 FROM #monthsales WHERE monthnr = 11 GROUP BY monthnr
SELECT monthnr, SUM(amount) AS SUM_MONTH_12 FROM #monthsales WHERE monthnr = 12 GROUP BY monthnr
-- END TEST CODE
END

Answer 1

You could declare a table variable (Declaring a variable of type table):
declare #MonthsSale table(monthnr int)
insert into #MonthsSale (monthnr) values (1)
insert into #MonthsSale (monthnr) values (2)
....
You can add extra columns as you like:
declare #MonthsSale table(monthnr int, totalsales tinyint)
You can update the table variable like any other table:
update m
set m.TotalSales = sum(s.SalesValue)
from #MonthsSale m
left join Sales s on month(s.SalesDt) = m.MonthNr

Answer 2

Is there a reason why you aren't using a table variable and the aggregate SUM operator, instead of a cursor? SQL excels at set-oriented operations. 99.87% of the time that you find yourself using a cursor, there's a set-oriented alternative that's more efficient:
declare #MonthsSale table
(
MonthNumber int,
MonthName varchar(9),
MonthSale decimal(18,2)
)
insert into #MonthsSale
select
1, 'January', 100.00
union select
2, 'February', 200.00
union select
3, 'March', 300.00
union select
4, 'April', 400.00
union select
5, 'May', 500.00
union select
6, 'June', 600.00
union select
7, 'July', 700.00
union select
8, 'August', 800.00
union select
9, 'September', 900.00
union select
10, 'October', 1000.00
union select
11, 'November', 1100.00
union select
12, 'December', 1200.00
select * from #MonthsSale
select SUM(MonthSale) as [TotalSales] from #MonthsSale

Answer 3

T-SQL doesn't support arrays that I'm aware of.
What's your table structure? You could probably design a query that does this instead:
select
month,
sum(sales)
from sales_table
group by month
order by month

Answer 4

Great question and great idea, but in SQL you'll need to do this:
For data type datetime, something like this-
declare #BeginDate datetime = '1/1/2016',
#EndDate datetime = '12/1/2016'
create table #months (dates datetime)
declare #var datetime = #BeginDate
while #var < dateadd(MONTH, +1, #EndDate)
Begin
insert into #months Values(#var)
set #var = Dateadd(MONTH, +1, #var)
end
If all you really want is numbers, do this-
create table #numbas (digit int)
declare #var int = 1 --your starting digit
while #var <= 12 --your ending digit
begin
insert into #numbas Values(#var)
set #var = #var +1
end

Answer 5

You can declare an array using the VALUES keyword. Your example can be expressed succintly in the following form:
SELECT * FROM (VALUES
(1,100),
(2,200),
(3,300),
(4,400),
(5,500),
(6,600),
(7,700),
(8,800),
(9,900),
(10,1000),
(11,1100),
(12,1200)
) MonthSale (monthnr, Amount)
Feel free to INSERT it into a table or place a WHERE or GROUP condition for your purposes.