Jooq：Select 计数组按

Question

I am trying to count the different possibilities of the gp_status field in my table. I have an sql query that works, just cant quite figure out how to transcribe it to Jooq.

select i.gp_status, COUNT(i.gp_status) 
from ideas_service.idea i 
group by i.gp_status 

So far in JOOQ i have this

var result = dsl.select(IDEA.GP_STATUS,count(),count(IDEA.GP_STATUS))
                .from(IDEA)
                .groupBy(IDEA.GP_STATUS)
                .fetch();

It looks like the fields comeback correctly, but i cant figure out how to extract them. I do know what the possible gp_status could be.

So i need to somehow get the row where gp_status = x

Answer 1

If you only need a single row

If you only need a single row, then you should add that predicate to your query, ie

var result = dsl.select(IDEA.GP_STATUS, count())
                .from(IDEA)
                .where(IDEA.GP_STATUS.eq("x"))
                .groupBy(IDEA.GP_STATUS)
                .fetchOne();

At which point you don't really need the GROUP BY clause anymore:

var result = dsl.select(count())
                .from(IDEA)
                .where(IDEA.GP_STATUS.eq("x"))
                .fetchOne();

Note that in both cases, I've used ResultQuery.fetchOne() , which produces a Record , from which you can extract the value in many ways, eg

// Repeat the column expression from the SELECT clause
int count1 = result.get(count());

// Access columns by index, and redundantly supply the type again
// Assuming the second query was executed
int count2 = result.get(0, int.class);

There are many more ways.

If you need the entire result

If you need the entire result set, but for a specific case, just want to extract one row, then you could iterate the Result , which extends List , or use Result.intoGroups(IDEA.GP_STATUS).get("x") or any other method on Result to do something similar.