基于条件构建器字符串-表达式quot为double-JPA

Question

New to CB, I'm trying to use it instead of native queries. The reason is I'll need different grouping by situations. Here's what I'm need to reproduce:

(1 - sum( field_1 [integer])::real / sum ( field_2 [integer])::real  ) * 100

Here's the code which suppose to do that:

Expression<Double> filed1Sum = cb.sumAsDouble(report.<Float>get("field1"));
Expression<Double> filed2Sum = cb.sumAsDouble(report.<Float>get("field2"));
Expression<Double> expected = cb.toDouble(cb.<Float>quot(filed1Sum, filed2Sum));

The problem is: the expected value is coming as Long!!! As the field1 is aways less than field2 I've got 0 (zero). I'm wondering get 0.888 something like that.

Answer 1

I've solved by multiplying the dividend by 1.0D:

Expression<Number> expected = cb.quot(cb.prod(filed1Sum,cb.literal(1.0D)), filed2Sum);

That generates the query:

(sum(field1) * 1.0) / sum(field2) 

Which returns a floating point correctly. No explicit conversions were required.

Thank you for the efforts to help me