Inserting data to a Room database

Question

When it comes to inserting data on a RoomDB, what is the best method to handle the conflict strategy? As i have tried.

@Insert(onConflict = @Insert(onConflict = OnConflictStrategy.REPLACE))

But it didn't work, as during conflict it sometimes duplicates and mess the auto increment on the plk values.

@Insert(onConflict = OnConflictStrategy.NONE)

But that sometimes does not replace, hence at sometimes I had to go back to use the first conflict strategy @Insert(onConflict = OnConflictStrategy.REPLACE)

The documentation is giving me two statements for the same function or library @Insert(onConflict = OnConflictStrategy.REPLACE) When you whover your mouse on "REPLACE" it says "OnConflict strategy constant to replace the old data and continue the transaction" on OnConflictStrategy.REPLACE where on OnConflictStrategy.NONE you get "OnConflict strategy constant used by default when no other strategy is set. Using it prevents Room from generating ON CONFLICT clause. It may be useful when there is a need to use ON CONFLICT clause within a trigger. The runtime behavior is the same as when ABORT strategy is applied. The transaction is rolled back"

But when you navigate to the implemantation or library object. you get something like "OnConflict strategy constant to rollback the transaction." on OnConflictStrategy.REPLACE where on OnConflictStrategy.NONE you get "OnConflict strategy constant to replace the old data and continue the transaction."

MikeT · Accepted Answer · 2024-03-20 22:18:45Z

1

mess the auto increment on the plk values

The intended use of a rowid, which a column with AUTOINCREMENT is an alias of, is to uniquely identify a row. If you are using the value in another way then you may well have issues.

The option that you appear to have dismissed is @Insert(onConflict = OnConflictStrategy.IGNORE). This will ignore the conflict and be reflected by the Long value returned by the @Insert returning -1 (instead of the generated value).

As such if you want to do an insert or replace without the potential issues with @Insert(onConflict = OnConflictStrategy.REPLACE) then you could either

use an @Upsert

or use code that ignores the conflict such as :-

@Insert(onConflict = OnConflictStrategy.IGNORE)
fun insert(whatever: WHATEVERCLASS): Long
@Update
fun update(whatever: WHATEVERCLASS): Int

@Transaction
@Query("")
@InsertOrUpdate(whatever: WHATEVECLASS)
    if (insert(whatever) < 1) {
        update(whatever)
    }   
}

NOTE in both circumstances reliance is made upon the primary key identifying the row to be updated.
if there are other constraints that result in a trappable conflict then the solution would be more complex.

edited Mar 20, 2024 at 22:18

answered Mar 20, 2024 at 19:50

MikeT

57.9k16 gold badges61 silver badges78 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Lloyd Munyai Over a year ago

Thank you @MikeT for responding to my problem. But @Insert(onConflict = OnConflictStrategy.IGNORE) It always cause duplicates when I try to do reports on the data I have on my Room, because I use Room just to store data incase I don't have connection to internet. Then when I get internet back, that's when I push data to my remote server, but then when i trace the records from the remote server I see lots of duplicates

Collectives™ on Stack Overflow

Inserting data to a Room database

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related