SQL Query - Year by Year Growth of Sales - sql-server

Question

I have this result set from an SQL query. This result has come up by grouping the sales of tenant per year to get the total sales in yearly basis. Table is named TENANTSALES with columns: Tenant, date, sales etc.
TENANT YEAR SALES
tenant 1 2014 2000
tenant 1 2015 5000
tenant 2 2013 1000
tenant 2 2014 1500
tenant 2 2015 800
I used this SQL query code to achieve the above result
select tenant, year(date), SUM(sales)
from tenantSales
group by tenant, YEAR(date)
What I need to complete the task is to add a column name Yearly growth where it will compare and compute for year by year growth of sales per tenant. Here's the sample correct / desired output
TENANT YEAR SALES YEARLY GROWTH
tenant 1 2014 2000
tenant 1 2015 5000 150%
tenant 2 2013 1000
tenant 2 2014 1500 50%
tenant 2 2015 800 -46.67%
The formula is: ((Latest Year - Previous Year) / Previous Year) * 100
Example for Tenant 1:
((2015 sales - 2014 sales) / 2014 sales) * 100 = 150%
Ive tried to do this, adding the next year in the previous year's row to make it easy for me to compute for the two years sales, but I can't add up the sales of the latest year, only the year itself. Is there any way or proper way to do it?
select tenantcode, year(date), SUM(gsc), year(date) + 1
from dailymod
where tenantcode = 'cmbina13'
group by tenantcode, YEAR(date)
Your expert advice will be highly appreciated. Thanks

Answer 1

Try this query:
SELECT t1.tenant, t1.YEAR, t1.SALES,
CASE WHEN t2.YEAR IS NOT NULL THEN
FORMAT(
CONVERT(DECIMAL(10, 2), (t1.SALES - t2.SALES)) /
CONVERT(DECIMAL(10, 2), t2.SALES), 'p')
ELSE NULL END AS "YEARLY GROWTH"
FROM
(
SELECT tenant, YEAR(date) AS YEAR, SUM(sales) AS SALES
FROM tenantSales
GROUP BY tenant, YEAR(date)
) t1
LEFT JOIN
(
SELECT tenant, YEAR(date) AS YEAR, SUM(sales) AS SALES
FROM tenantSales
GROUP BY tenant, YEAR(date)
) t2
ON t1.tenant = t2.tenant AND t2.YEAR = t1.YEAR - 1
Click the link below for a working demo:
SQLFiddle
Late Update:
You could also try the same approach using Common Table Expressions. Here is what the above query would look like using this approach:
WITH cte AS(SELECT tenant, YEAR(date) AS YEAR, SUM(sales) AS SALES
FROM tenantSales
GROUP BY tenant, YEAR(date))
SELECT c1.*, CONVERT(varchar,
CONVERT(DECIMAL(10,2),
CONVERT(DECIMAL(10, 2), (c1.SALES - c2.SALES)) /
CONVERT(DECIMAL(10, 2), c2.SALES))) + '%' AS "YEARLY GROWTH"
FROM cte c1
LEFT JOIN cte c2 ON c1.tenant = c2.tenant AND c2.YEAR = c1.YEAR - 1
And here is another Fiddle where you can test this out:
SQLFiddle

Answer 2

Using cte you can reuse your query. I am using window function because you can have some missed years. But if years are consecutive then you can join directly on year column:
with cte as(select tenant,
year(date) y,
SUM(sales) s,
row_number() over(partition by tenant order by sum(sales)) rn
from tenantSales
group by tenant, YEAR(date))
select c1.*, ((c1.s - c2.s) / c2.s) * 100 as grouth
from cte c1
left join cte c2 on c1.tenant = c2.tenant and c1.rn = c2.rn + 1
Or:
with cte as(select tenant, year(date) y, SUM(sales) s
from tenantSales
group by tenant, YEAR(date))
select c1.*, ((c1.s - c2.s) / c2.s) * 100 as grouth
from cte c1
left join cte c2 on c1.tenant = c2.tenant and c1.y = c2.y + 1

Answer 3

please consider my answer with analytical function.
select tenant ,year(date) ,sum(sales),
format( ((sum(sales)/convert(float,lag(sum(sales)) over( partition by tenant order by tenant,year(date))))-1),'p')
from tenantSales
group by tenant , year(date)

Answer 4

select tenant_id
,year
,sales
, round((case when chk<>0 then ((sales-chk)/chk)*100 else 0 end),2)as yoy
from(
select tenant_id
,year
,sales
,lag(sales,1,0) over(partition by tenant_id order by year asc) as chk
from tenant)

Answer 5

Please find the below solution.
create table tenant_details
(tenant varchar(10),
year number(10),
sales number(10)
);
insert into tenant_details values ('tenant 1',2014,2000);
insert into tenant_details values ('tenant 1',2015,5000);
insert into tenant_details values ('tenant 2',2013,1000);
insert into tenant_details values ('tenant 2',2014,1500);
insert into tenant_details values ('tenant 2',2015,800);
commit;
SQL Query:
select tenant,year,sales,case when prev_sales is null then null else
to_char((sales-prev_sales)*100/prev_sales,9999.9) ||'%' end profit
from (
select tenant,year,sales ,lag(sales,1) over (partition by tenant order by year) prev_sales from tenant_details
);