Question

I’ll try and describe best I can. Working with a bad data model.

Table1
id, name, area, bla1, bla2, bla3

Table2
table1_ID, stuff1, stuff2, ID

trigger on table1
insert row in table2 if table1 is updated

In table1 I have 10 different area, only 186 rows, not so much I can’t do this manually in like 2 seconds with Excel but I want to create realtime report.

The report would be

area1 - %complete
area2 - %complete
area3 - %complete
etc.....

When a row is updated in table1 the trigger inserts some stuff in table2 indicating ‘complete’.

I can do (probably really bad form)

select
(select count(*) from table1 a where a.id in (select id from table2))
/
(select count(*) from table1)
*100

This gives me an overall percentage complete.
I was thinking of adding where clauses to each of the selects, hard coding ‘area’ and then union TEN times. Ugh, tell me there is a better way to get this in one report.

Obviously this query is a fail

select area,
(
(select count(*) from table1 a where a.id in (select id from table2))
/
(select count(*) from table1)
*100) from table1
group by area

I figure group by has got to fit in there somewhere. Thanks in advance!

Answer 1

select area, count(table2.table1_ID) / count(table1.id)
from table1 left join table2 on table1.id = table2.table1_ID
group by area