It looks as if you’ve made progress translating PREV. So, well done. That was a hard problem that I hadn’t managed to make progress on.
Regarding "p0.commission && p2.commission && p4.commission > p6.commission”. Those first two terms look a lot like “is null” checks that Linq4j inserts sometimes. So, I surmise that the converter is suffering an off-by-one (or off-by-N) error and using the wrong expressions. Julian > On Mar 31, 2019, at 9:45 AM, Julian Feinauer <[email protected]> > wrote: > > Hi all, > > I have some problems with the code generation from Linq4j which I'm unable to > resolve myself. > Basically, I want to translate a condition from Rex to a Linq4j expression to > use it in generated code. > In my example the Condition is from Match Recognize and in SQL is: > `up."commission" > prev(up."commission")`. > > ``` > RexBuilder rexBuilder = new RexBuilder(implementor.getTypeFactory()); > RexProgramBuilder rexProgramBuilder = new > RexProgramBuilder(physType.getRowType(), rexBuilder); > > rexProgramBuilder.addCondition(entry.getValue()); > > final Expression condition = > RexToLixTranslator.translateCondition(rexProgramBuilder.getProgram(), > (JavaTypeFactory) getCluster().getTypeFactory(), > builder2, > inputGetter1, > implementor.allCorrelateVariables, > implementor.getConformance()); > > > builder2.add(Expressions.return_(null, condition)); > ``` > > Here, the condition seems okay, it is: ">(PREV(UP.$4, 0), PREV(UP.$4, 1))", > so it should be a comparison of two variables (I rewrite the PREV with a > custom Input Getter". > But, the generated code (for Janino) is: > > ``` > Object p1 = row_.get($L4J$C$0_1); > org.apache.calcite.test.JdbcTest.Employee p0 = > (org.apache.calcite.test.JdbcTest.Employee) p1; > Object p3 = row_.get($L4J$C$1_1); > org.apache.calcite.test.JdbcTest.Employee p2 = > (org.apache.calcite.test.JdbcTest.Employee) p3; > Object p5 = row_.get($L4J$C$0_1); > org.apache.calcite.test.JdbcTest.Employee p4 = > (org.apache.calcite.test.JdbcTest.Employee) p5; > Object p7 = row_.get($L4J$C$1_1); > org.apache.calcite.test.JdbcTest.Employee p6 = > (org.apache.calcite.test.JdbcTest.Employee) p7; > return p0.commission && p2.commission && p4.commission > p6.commission; > ``` > > This confuses me a lot as I do not know where the check for p0.commission and > p2.commission comes from. > It seems that Linq4j adds them as it expects these variables to be nullable, > but I have no idea on how to avoid this. > These fields are Numeric so I always get a compilation exception. > > Can someone help me with this issue? > > Thanks! > Julian >
