Sum and count of records - sql

Question

I have a table with some records:
Col1
Col2
Col3
Col4
1
Row1
99
152
1
Row2
99
20
5
Row3
98
34
1
Row4
120
18
7
Row5
27
74
I need to get the sum of Col4 values where Col1 = 1, sum of Col4 values where Col3 = 99 and Col1 = 1, sum of Col4 values where Col3 <> 99 and Col1 = 1, total count of records where Col1 = 1, count of records where Col3 = 99 and Col1 = 1, count of records where Col3 <> 99 and Col1 = 1 (there is a possibility that there will be no records that meet the criteria).
My SQLite statement looks like that:
query.SQL.Text:= 'SELECT IFNULL(sum(Col4), 0), '+
'IFNULL(sum(case when Col3 = 99 then Col4 else 0 end), 0), ' +
'IFNULL(sum(case when Col3 <> 99 then Col4 else 0 end), 0), ' +
'IFNULL(count(*), 0), ' +
'IFNULL(sum(case Col3 = 99 then 1 else 0 end), 0), ' +
'IFNULL(sum(case Col3 <> 99 then 1 else 0 end), 0) ' +
'FROM myTable WHERE Col1 = :_Col1';
Is there a way to simplify it?

Answer 1

SQLite evaluates boolean expressions to 1 (true) or 0 (false), so a CASE expression like:
case when Col3 = 99 then 1 else 0 end
can be simplified to:
Col3 = 99
Also, the ELSE part in a CASE expression like:
CASE WHEN Col3 = 99 THEN Col4 ELSE 0 END
is not needed because later you use IFNULL() to return 0 in case it returns NULL.
Finally, COUNT(*) never returns NULL, so IFNULL() is not needed in this case.
Simplify your code to this:
SELECT IFNULL(SUM(Col4), 0),
IFNULL(SUM(CASE WHEN Col3 = 99 THEN Col4 END), 0),
IFNULL(SUM(CASE WHEN Col3 <> 99 THEN Col4 END), 0),
COUNT(*),
IFNULL(SUM(Col3 = 99), 0),
IFNULL(SUM(Col3 <> 99), 0)
FROM myTable
WHERE Col1 = 1;
See the demo.