I've a table with accounts and another with transactions:

```
@Parcelize
@Entity(tableName = Database.Accounts.TABLE_NAME)
data class Account(
    @PrimaryKey(autoGenerate = true) @ColumnInfo(name = Database.Accounts.COL_ID) val id: Long = 0,
    @ColumnInfo(name = Database.Accounts.COL_NAME) val name: String = "",
    @ColumnInfo(name = Database.Accounts.COL_BALANCE) val balance: Double = 0.0
) : Model

```

Each transactions belongs to an account and therefore holds an `account_id`.

```
data class TransactionEntity(
    @PrimaryKey(autoGenerate = true) @ColumnInfo(name = Database.Transactions.COL_ID) val id: Long = 0L,
    @ColumnInfo(name = Database.Transactions.COL_TITLE) val title: String = "",
    @ColumnInfo(name = Database.Transactions.COL_DATE) val date: LocalDate = LocalDate.MIN,
    @ColumnInfo(name = Database.Transactions.COL_VALUE) val value: Double = 0.0,
    @ColumnInfo(name = Database.Transactions.COL_NOTES) val notes: String = "",
    @ColumnInfo(name = Database.Transactions.COL_TYPE) @TransactionType val type: Int = TransactionType.EARNING,
    @ColumnInfo(name = Database.Transactions.COL_ACCOUNT_ID) val accountId: Long = Account.DEFAULT_ACCOUNT_ID,
    @ColumnInfo(name = Database.Transactions.COL_BUDGET_ID) val budgetId: Long? = null
) : Model

```

When querying accounts, the `balance` should be the summed `value` of all transactions belonging to the account.

How can I realize that?