Bug for SqlType.transform when transforming database null values of JVM primitive types.

[vincentlauvlwj]

Code to reproduce this issue:

enum class Status(val code: Int) {
    ONE(1), TWO(2), THREE(3);

    companion object {
        fun forCode(code: Int): Status {
            return values().first { it.code == code }
        }
    }
}

@Test
fun testTransformingNullValues() {
    val t = object : Table<Nothing>("T_TEST_TRANSFORMING_NULL_VALUES") {
        val status = int("STATUS").transform({ Status.forCode(it) }, { it.code })
    }

    database.useConnection { conn ->
        conn.createStatement().use { statement ->
            val sql = """CREATE TABLE T_TEST_TRANSFORMING_NULL_VALUES(STATUS INT)"""
            statement.executeUpdate(sql)
        }
    }

    database.insert(t) {
        set(it.status, null)
    }

    val query = database.from(t).select(t.status)
    assert(query.map { row -> row[t.status] }.first() == null)
}

Throwing the exception:

[zuisong]

Maybe you can change your code to this

enum class Status(val code: Int) {
    ONE(1), TWO(2), THREE(3);

    companion object {
        fun forCode(code: Int?): Status? {
            return values().firstOrNull { it.code == code }
        }
    }
}