CODEWITHSUNDEEP
androidkotlinandroid-roomdao
Admire Masaga
Admire Masaga

Reputation: 61

kotlin Not sure how to handle insert method's return type

i am developing an android application using kotlin and room library. when i try to get the id of the inserted item i am getting the following error

Not sure how to handle insert method's return type. public abstract java.lang.Object insertReceipt(@org.jetbrains.annotations.NotNull()

i have tried other solutions like this but it is not working

here is my code

Receipt.kt

@Entity
data class Receipt(
    @ColumnInfo() val receipt_timestamp: Timestamp,
    @ColumnInfo() val receipt_items: Int,
    @ColumnInfo() val receipt_total_price: BigDecimal
){
    @PrimaryKey(autoGenerate = true)
    var receiptNo: Int = 0
}

ReceiptDao.kt

@Insert()
    suspend fun insertReceipt(receipt: Receipt): Int

ReceiptRepository.kt

suspend fun insertReceipt(receipt: Receipt): Int{
        return receiptDAO.insertReceipt(receipt)
    }

Upvotes: 1

Views: 2377

Answers (2)

Manuel Mato
Manuel Mato

Reputation: 779

A method annotated with the @Insert annotation can return:

    long for single insert operation
    long[] or Long[] or List for multiple insert operations
    void if you don't care about the inserted id(s)

So you must change your return type of insertReceipt from Int to Long:

return receiptDAO.insertReceipt(receipt).toLong()

Upvotes: 1

benjiii
benjiii

Reputation: 553

That is because you cannot get the id like this. You can get an id with this function but it will not be the one you want.

cf: https://developer.android.com/training/data-storage/room/accessing-data#convenience-insert the id returned is an internal id used by sqlite.

To achieve what you want, you need something like: 

@Query("SELECT receiptNo FROM receipt WHERE receipt_timestamp = :receipt_timestamp AND receipt_items = : receipt_items AND receipt_total_price = :receipt_total_price LIMIT 1")
fun getId(receipt_timestamp: Timestamp, receipt_items: Int, receipt_total_price: BigDecimal): Int

Upvotes: 1

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