可空CompositeMoneyColumn，如何分配一个可空的MonetaryAmount？

Question

我有一个这样的专栏：

val notNullableAmount = compositeMoney(DECIMAL_PRECISION,
    DECIMAL_SCALE,
    "principal_sum",
    "principal_sum_currency")

在本例中，我可以将MonetaryAmount类型的值赋值给列，如下所示：

it[notNullableAmount] = ggnCollectionDocument.principalSum!!

但是，当我使用nullable()时，比如：

val principalSum = compositeMoney(DECIMAL_PRECISION,
    DECIMAL_SCALE,
    "principal_sum",
    "principal_sum_currency").nullable()

那么我就不能再分配MonetaryAmount了。它抱怨了一些通用的错误消息：

None of the following functions can be called with the arguments supplied.
set(Column<TypeVariable(ID)>, TypeVariable(E))   where S = TypeVariable(S), ID = TypeVariable(ID), E = TypeVariable(E) for    fun <S, ID : EntityID<S>, E : Expression<S>> set(column: Column<ID>, value: E): Unit defined in org.jetbrains.exposed.sql.statements.InsertStatement
set(Column<TypeVariable(ID)>, TypeVariable(S))   where S = TypeVariable(S), E = TypeVariable(E), ID = TypeVariable(ID) for    fun <S : Comparable<S>, E : S, ID : EntityID<E>?> set(column: Column<ID>, value: S): Unit defined in org.jetbrains.exposed.sql.statements.InsertStatement
set(Column<TypeVariable(S)>, TypeVariable(S))   where S = TypeVariable(S) for    fun <S> set(column: Column<S>, value: S): Unit defined in org.jetbrains.exposed.sql.statements.InsertStatement
set(Column<TypeVariable(S)>, Query)   where S = TypeVariable(S) for    fun <S> set(column: Column<S>, value: Query): Unit defined in org.jetbrains.exposed.sql.statements.InsertStatement
set(Column<TypeVariable(T)>, TypeVariable(E))   where T = TypeVariable(T), S = TypeVariable(S), E = TypeVariable(E) for    fun <T, S : T, E : Expression<S>> set(column: Column<T>, value: E): Unit defined in org.jetbrains.exposed.sql.statements.InsertStatement
set(CompositeColumn<TypeVariable(S)>, TypeVariable(S))   where S = TypeVariable(S) for    fun <S : Any> set(column: CompositeColumn<S>, value: S): Unit defined in org.jetbrains.exposed.sql.statements.InsertStatement

Answer 1

在表的声明中：

val principalSum = (compositeMoney(DECIMAL_PRECISION,
    DECIMAL_SCALE,
    "principal_sum",
    "principal_sum_currency").nullable()) as CompositeMoneyColumn<*, *, MonetaryAmount?>

在用法上：

it[principalSum] = ggnCollectionDocument.principalSum

与过载操作员：

private operator fun InsertStatement<*>.set(column: CompositeMoneyColumn<*,*,MonetaryAmount?>, value: MonetaryAmount?) {
   val insertStatement = this
   insertStatement.set(column.amount as Column<BigDecimal?>, value?.number?.numberValue(BigDecimal::class.java))
   insertStatement.set(column.currency as Column<CurrencyUnit?>, value?.currency)
}