How to pivot and merge to avoid the NULL cells? - tsql

Question

Sample table data:
SELECT [id],[date],[agent],[sales]
FROM [AgentSales]
id date agent sales
1 2021-01-02 00:00:00.000 Agent A 10
2 2021-01-03 00:00:00.000 Agent A 2
3 2021-01-04 00:00:00.000 Agent B 22
4 2021-01-06 00:00:00.000 Agent B 5
5 2021-02-05 00:00:00.000 Agent A 1
6 2021-02-06 00:00:00.000 Agent B 33
7 2021-03-06 00:00:00.000 Agent A 11
8 2021-03-06 00:00:00.000 Agent B 3
Group by YearMonth, Agent:
SELECT CAST(YEAR([DATE]) AS VARCHAR)+' '+CAST(MONTH([DATE]) AS VARCHAR) YRMON, AGENT, SUM(SALES) SALES
FROM AgentSales
GROUP BY CAST(YEAR([DATE]) AS VARCHAR)+' '+CAST(MONTH([DATE]) AS VARCHAR), AGENT
ORDER BY 1
YRMON AGENT SALES
2021 1 Agent A 12
2021 1 Agent B 27
2021 2 Agent A 1
2021 2 Agent B 33
2021 3 Agent A 11
2021 3 Agent B 3
PIVOT:
SELECT CAST(YEAR([DATE]) AS VARCHAR)+' '+CAST(MONTH([DATE]) AS VARCHAR) YRMON, [AGENT A], [AGENT B]
FROM AgentSales
PIVOT (SUM(SALES) FOR AGENT IN ([AGENT A], [AGENT B])) AS PIVOTTABLE
YRMON AGENT A AGENT B
2021 1 10 NULL
2021 1 2 NULL
2021 1 NULL 22
2021 1 NULL 5
2021 2 1 NULL
2021 2 NULL 33
2021 3 11 NULL
2021 3 NULL 3
I want to have the actual value in place of the NULLs. So effectively there should be only 2 rows for each YearMon. How to do this?
Expected result:
YRMON AGENT A AGENT B
2021 1 12 27
2021 2 1 33
2021 3 11 3

Answer 1

Looks like simple conditional aggregation should do the trick.
SELECT
FORMAT(EOMONTH([DATE]), 'yyyy MM') YRMON,
SUM(CASE WHEN AGENT = 'AGENT B' THEN SALES END) [AGENT B],
SUM(CASE WHEN AGENT = 'AGENT A' THEN SALES END) [AGENT A]
FROM AgentSales
GROUP BY EOMONTH([DATE])
ORDER BY EOMONTH([DATE]);
Or if you want each one on a separate row, you can add in a row-number and group on that
SELECT
FORMAT(EOMONTH([DATE]), 'yyyy MM') YRMON,
SUM(CASE WHEN AGENT = 'AGENT B' THEN SALES END) [AGENT B],
SUM(CASE WHEN AGENT = 'AGENT A' THEN SALES END) [AGENT A]
FROM (
SELECT *,
rn = ROW_NUMBER() OVER (PARTITION BY EOMONTH([DATE]), AGENT ORDER BY [DATE])
FROM AgentSales
) sales
GROUP BY EOMONTH([DATE]), rn
ORDER BY EOMONTH([DATE]), rn;
Grouping by EOMONTH is more performant than grouping by a string
db<>fiddle