fix!: EXPOSED-825 Case().When(...).Else(...) with QueryParameter(...,…

[obabichevjb]

We've got a list of example where case() could be working, but it's not:

Count(case(CheckIns.checkInMethod).When(CheckInMethod.CODE, 1))  // CE: 1 is type-mismatching
Count(case(CheckIns.checkInMethod).When(CheckInMethod.CODE, intLiteral(1)))  // CE: CheckInMethod.CODE isn't a Boolean expression
Count(case().When(CheckIns.checkInMethod eq CheckInMethod.CODE, intLiteral(1)))  // CE: CaseWhen is not an expression
Count(case().When(CheckIns.checkInMethod eq CheckInMethod.CODE, intLiteral(1)).Else(null))  // CE: null is type-mismatching
Sum(case().When(CheckIns.checkInMethod eq CheckInMethod.CODE, intLiteral(1)).Else(intLiteral(0)))  // CE: no column type
Sum(case().When(CheckIns.checkInMethod eq CheckInMethod.CODE, intLiteral(1)).Else(intLiteral(0)), IntegerColumnType())  // success

With this PR Case was spit to Case and ValueCase classes. With this change it's getting possible to allow pass kotlin values instead of expressions into When/Else parts of the case() statement.

Also new variant allows to create statement without Else() part, what was not possible before.

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Type of Change

Please mark the relevant options with an "X":

• Bug fix

Updates/remove existing public API methods:

• Is breaking change

Affected databases:

• All

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Related Issues

EXPOSED-825 Case().When(...).Else(...) with QueryParameter(..., EnumerationColumnType) throws “No column type has been found”

[e5l]

please check if the breaking change document should be adjusted as well

[bog-walk]

Please check comments, particularly about When(literal, literal) and breaking changes.

[bog-walk]

This is the only new method that gives me pause, as I thought making resultType optional would always throw at runtime. But now I assume it must be for chained WHEN clauses, but it seems to be order-based?

Is the following expected?

// successful
case(tester.key)
    .When(0, 100, IntegerColumnType())
    .When(1, 200)
    .Else(10)
    .let { expr ->
        tester.select(expr).where { tester.key eq 0 }.first()
    }

// fails with -> No column type has been found
case(tester.key)
    .When(0, 100)
    .When(1, 200, IntegerColumnType())
    .Else(10)
    .let { expr ->
        tester.select(expr).where { tester.key eq 0 }.first()
    }

Seems a little odd.
But if it is expected (or unavoidable), can it at least be mentioned in the KDocs? That the first chained use of this method must always have a provided type?

[obabichevjb]

I updated the KDoc to mention that column type should be provided in the beginning of the chain.

But I also imrpoved it a bit with resolveColumnType(), so primitives could be used in When without explicit providing of column type.