T-SQL: Rows to Columns - sql

Question

I am a SQL beginner, so can anyone please help me with this?
I have a table like this
YearMonth | Customer | Currency | BusinessType | Amount
04-2020 | 123 | EUR | Budget | 500
04-2020 | 123 | EUR | Forecast | 300
04-2020 | 123 | EUR | Sales | 700
And now I need it like:
YearMonth | Customer | Currency | Amount Budget | Amount Forecast | Amount Sales
04-2020 | 123 | EUR | 500 | 300 | 700
Is something like this possible?
Thanks in advance for your help!

Answer 1

Use conditional aggregation:
select yearmonth, customer, currency,
sum(case when businesstype = 'Budget' then amount end) as budget,
sum(case when businesstype = 'Forecast' then amount end) as forecast,
sum(case when businesstype = 'Sales' then amount end) as sales
from t
group by yearmonth, customer, currency;

Answer 2

You can do aggregation :
select yearmonth, customer, currency,
sum(case when businesstype = 'budget' then amount else 0 end),
sum(case when businesstype = 'Forecast' then amount else 0 end),
sum(case when businesstype = 'Sales' then amount else 0 end)
from table t
group by yearmonth, customer, currency;

Answer 3

Also, you may want to add an "Other" to capture any new Business Types:
select yearmonth, customer, currency,
sum(case when businesstype = 'Budget' then amount end) as budget,
sum(case when businesstype = 'Forecast' then amount end) as forecast,
sum(case when businesstype = 'Sales' then amount end) as sales,
sum(case when businesstype not in ('Budget', 'Forecast', 'Sales') then amount end) as other
from t
group by yearmonth, customer, currency;

Answer 4

This type of requirements are usually resolved using T-SQL PIVOT relational operation (https://learn.microsoft.com/en-us/sql/t-sql/queries/from-using-pivot-and-unpivot?view=sql-server-ver15). For the above example I used the following query to achieve this:
-- Create a temporary table to store the data.
IF (OBJECT_ID('tempdb..##temp2') IS NOT NULL) DROP TABLE ##temp2
CREATE TABLE ##temp2 (Id int IDENTITY (1,1) PRIMARY KEY, YearMonth varchar(100), Customer int, Currency varchar(100), BusinessType varchar(100), Amount int)
INSERT ##temp2
VALUES
('04-2020', 123,'EUR','Sales', 700),
('04-2020', 123,'EUR','Budget', 500),
('04-2020', 123,'EUR','Forecast', 300)
-- Using PIVOT allows you to move rows into columns
SELECT pivot_table.YearMonth,
pivot_table.Customer,
pivot_table.Currency,
[Amount Forecast] = pivot_table.Forecast,
[Amount Budget] = pivot_table.Budget,
[Amount Sales] = pivot_table.Sales
FROM
(
SELECT YearMonth,
Customer,
Currency,
BusinessType,
Amount
FROM ##temp2
) t
PIVOT
(
SUM(Amount)
FOR BusinessType IN ([Sales], [Budget], [Forecast])
) AS pivot_table;