mcpierce

mcpierce

Kotlin and Android Development featuring Jetpack: Unique constraint error when running chapter 5 code changes

@mfazio23

I’ve applied the changes from Chapter 5 of the book and everything builds correctly and runs. But, when I try to start a game, the following exception is being thrown:

android.database.sqlite.SQLiteConstraintException: UNIQUE constraint failed: game_statuses.gameId, game_statuses.playerId (code 1555 SQLITE_CONSTRAINT_PRIMARYKEY)
    at android.database.sqlite.SQLiteConnection.nativeExecuteForLastInsertedRowId(Native Method)
    at android.database.sqlite.SQLiteConnection.executeForLastInsertedRowId(SQLiteConnection.java:940)
    at android.database.sqlite.SQLiteSession.executeForLastInsertedRowId(SQLiteSession.java:790)
    at android.database.sqlite.SQLiteStatement.executeInsert(SQLiteStatement.java:89)
    at androidx.sqlite.db.framework.FrameworkSQLiteStatement.executeInsert(FrameworkSQLiteStatement.kt:42)
    at androidx.room.EntityInsertionAdapter.insert(EntityInsertionAdapter.kt:85)
    at dev.mfazio.pennydrop.data.PennyDropDao_Impl$10.call(PennyDropDao_Impl.java:278)
    at dev.mfazio.pennydrop.data.PennyDropDao_Impl$10.call(PennyDropDao_Impl.java:273)
   <snipped>

Any suggestion on what to check in the project code?

Marked As Solved

mfazio23

mfazio23

Author of Kotlin and Android Development featuring Jetpack

Apologies for losing track of this thread, but on the plus side, I see what’s going on. It took me a bit to find, too, since it wasn’t clear right away.

Quick version:
You’re missing android:text="@={player.playerName}" on the @+id/edit_text_player_name <Edit Text> in player_list_item.xml.

Long version:
The database exception happens because the game sees you as trying to enter in the same player twice, meaning both players have the same ID. They both are seen as having the same ID because of how the app gets players in PennyDropDao:

// PennyDropDao.startGame(...)
val playerIds = players.map { player -> 
    getPlayer(player.playerName)?.playerId ?: insertPlayer(player)
}

We get players by name from the DB or create new versions. If two players have the same name (even if it’s a blank name), one is inserted into the DB and the other is retrieved right away, but they’re both the same.

In this issue’s case, the names were blank because nothing was in place to assign the name to the playerName field. That lives inside player_list_item.xml and the edit_text_player_name <EditText>.

If you don’t have a value set for android:text, a TextView will still show what you type in, but nothing happens with it. You need to set an expression there (with the = after the @) to link it back to the NewPlayer object:

android:text="@={player.playerName}"

While the error makes sense in the end, it’s almost misleading given where the issue starts out.

Where Next?

Popular Pragmatic Bookshelf topics Top

jimmykiang
This test is broken right out of the box… — FAIL: TestAgent (7.82s) agent_test.go:77: Error Trace: agent_test.go:77 agent_test.go:...
New
johnp
Running the examples in chapter 5 c under pytest 5.4.1 causes an AttributeError: ‘module’ object has no attribute ‘config’. In particula...
New
jesse050717
Title: Web Development with Clojure, Third Edition, pg 116 Hi - I just started chapter 5 and I am stuck on page 116 while trying to star...
New
jamis
The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...
New
herminiotorres
Hi! I know not the intentions behind this narrative when called, on page XI: mount() |&gt; handle_event() |&gt; render() but the correc...
New
leba0495
Hello! Thanks for the great book. I was attempting the Trie (chap 17) exercises and for number 4 the solution provided for the autocorre...
New
Charles
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
New
AufHe
I’m a newbie to Rails 7 and have hit an issue with the bin/Dev script mentioned on pages 112-113. Iteration A1 - Seeing the list of prod...
New
mcpierce
@mfazio23 I’ve applied the changes from Chapter 5 of the book and everything builds correctly and runs. But, when I try to start a game,...
New
dachristenson
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
New

Other popular topics Top

Devtalk
Hello Devtalk World! Please let us know a little about who you are and where you’re from :nerd_face:
New
Rainer
My first contact with Erlang was about 2 years ago when I used RabbitMQ, which is written in Erlang, for my job. This made me curious and...
New
AstonJ
Just done a fresh install of macOS Big Sur and on installing Erlang I am getting: asdf install erlang 23.1.2 Configure failed. checking ...
New
PragmaticBookshelf
“A Mystical Experience” Hero’s Journey with Paolo Perrotta @nusco Ever wonder how authoring books compares to writing articles?...
New
wmnnd
Here’s the story how one of the world’s first production deployments of LiveView came to be - and how trying to improve it almost caused ...
New
PragmaticBookshelf
Author Spotlight Jamis Buck @jamis This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
New
husaindevelop
Inside our android webview app, we are trying to paste the copied content from another app eg (notes) using navigator.clipboard.readtext ...
New
AstonJ
If you’re getting errors like this: psql: error: connection to server on socket “/tmp/.s.PGSQL.5432” failed: No such file or directory ...
New
AnfaengerAlex
Hello, I’m a beginner in Android development and I’m facing an issue with my project setup. In my build.gradle.kts file, I have the foll...
New

Sub Categories: