Reputation: 127
I have a set of data that is divided by the department, fiscal year, fiscal quarter and finally total amount, similar to below.
+---------------------------------+------------+---------------+-------------+
| Department | FISCALYEAR | FISCALQUARTER | TotalAmount |
+---------------------------------+------------+---------------+-------------+
| Internal Medicine - Dermatology | 2018 | 2 | 50.00 |
| Internal Medicine - Dermatology | 2018 | 4 | 75.00 |
| Internal Medicine - Dermatology | 2019 | 1 | 135.00 |
| Internal Medicine - Dermatology | 2019 | 2 | 75.00 |
| Internal Medicine - Dermatology | 2019 | 3 | 185.00 |
| Internal Medicine - Dermatology | 2019 | 4 | 84.00 |
| Internal Medicine - Dermatology | 2020 | 1 | 85.00 |
| Internal Medicine - Dermatology | 2020 | 2 | 10.00 |
+---------------------------------+------------+---------------+-------------+
How would I add a column to get the total amount from the previous year/quarter? For instance fiscal year 2020, fiscal quarter 2 would show 75.00.
The tough part is that some quarters don't have any data, so there are gaps.
I have attempted a LAG() window function, but have difficulties on specifying the offset since it is not a standard offset.
Any help/ideas would be great.
Upvotes: 0
Views: 133
Reputation: 1269703
Assuming you have data for every year, use window functions:
SELECT a.Department, a.FISCALYEAR, a.FISCALQUARTER,
a.TotalAmount,
LAG(a.TotalAmount) OVER (PARTITION BY a.Department, a.FISCALQUARTER ORDER BY a.FISCALYEAR) AS PriorYearQuarterTotalAmount
FROM a;
Window functions generally result in the fastest queries and are more concise than alternatives.
Upvotes: 0
Reputation: 3363
How about this?
IF OBJECT_ID('tempdb.dbo.#YourTable', 'U') IS NOT NULL DROP TABLE #YourTable;
CREATE TABLE #YourTable(
Department VARCHAR(33) NOT NULL
,FISCALYEAR INTEGER NOT NULL
,FISCALQUARTER INTEGER NOT NULL
,TotalAmount NUMERIC(7,2) NOT NULL
);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2018,2,50.00);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2018,4,75.00);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2019,1,135.00);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2019,2,75.00);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2019,3,185.00);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2019,4,84.00);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2020,1,85.00);
INSERT INTO #YourTable(Department,FISCALYEAR,FISCALQUARTER,TotalAmount) VALUES ('Internal Medicine - Dermatology',2020,2,10.00);
SELECT a.Department, a.FISCALYEAR, a.FISCALQUARTER,
a.TotalAmount, b.TotalAmount AS PriorYearQuarterTotalAmount
FROM #YourTable a
LEFT JOIN #YourTable b ON a.Department = b.Department
AND a.FISCALYEAR - 1 = b.FISCALYEAR
AND a.FISCALQUARTER = b.FISCALQUARTER
Upvotes: 1
Reputation: 222442
You could use an inline query:
select
t.*,
(
select t1.TotalAmount
from mytable t1
where t1.FiscalQuarter = t.FiscalQuarter and t1.FiscalYear = t.FiscalYear - 1
) lastTotalAmount
from mytable t
Upvotes: 0