房间自动迁移不起作用：新表（实体）的致命异常

Question

After trying to use auto migration for a new entity/table i found this error.

E/AndroidRuntime: FATAL EXCEPTION: main
Process: net.sharetrip.b2b, PID: 8861
java.lang.IllegalStateException: Migration didn't properly handle: QuickPassenger(net.sharetrip.b2b.view.more.model.QuickPassenger).
 Expected:
TableInfo{name='QuickPassenger', columns={passportNumber=Column{name='passportNumber', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, lastName=Column{name='lastName', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, wheelChair=Column{name='wheelChair', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, gender=Column{name='gender', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, mealPreference=Column{name='mealPreference', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, mobileNumber=Column{name='mobileNumber', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, dateOfBirth=Column{name='dateOfBirth', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, firstName=Column{name='firstName', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, seatPreference=Column{name='seatPreference', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, titleName=Column{name='titleName', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, nationality=Column{name='nationality', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=0, defaultValue='null'}, frequentFlyerNumber=Column{name='frequentFlyerNumber', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, passportCopy=Column{name='passportCopy', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, passportExpireDate=Column{name='passportExpireDate', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, id=Column{name='id', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=1, defaultValue='null'}, visaCopy=Column{name='visaCopy', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, travellerType=Column{name='travellerType', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, email=Column{name='email', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}}, foreignKeys=[], indices=[]}
 Found:
TableInfo{name='QuickPassenger', columns={}, foreignKeys=[], indices=[]}
    at androidx.room.RoomOpenHelper.onUpgrade(RoomOpenHelper.java:103)

It seems that no columns found when the migration occurs. I declared my entitity like below.

@Entity
data class QuickPassenger(
    @PrimaryKey
    @ColumnInfo(name = "id")
    var id: String,
    var titleName: String?,
    var firstName: String?,
    var lastName: String?,
    var gender: String? = Gender.male,
    var nationality: String = "BD",
    var dateOfBirth: String?,
    var passportNumber: String?,
    var frequentFlyerNumber: String?,
    var passportExpireDate: String?,
    var seatPreference: String?,
    var mealPreference: String?,
    var wheelChair: String?,
    var passportCopy: String?,
    var visaCopy: String?,
    val travellerType: String?,
    val email: String?,
    val mobileNumber: String?
)

I am using 2.4.0-alpha04 version of room for all

androidx.room:room-compiler 
androidx.room:room-ktx
androidx.room:room-runtime. 

Any help is highly appreciated.

Answer 1

It's related to your database version and schemas. After entity creation (or other database schemas changes), if you build and run the project without increasing the database version or defining the auto-migration, then the app database may be damaged.
So, you need to increase the database version (eg from v1 to v2) and define the auto-migration (as the docs ) first, then build and run the project.
In your case (that the app database is probably broken), I suggest you uninstall the app, rollback (or stash) your changes, run the project, apply all the entity creation and auto-migration stuffs again, and re-run the project.
But before re-run, be sure that your old database schemas file has not changed (look for file 1.json as my example). Instead, by increasing the database version and re-run the project, the new database schemas file should be auto-generated (look for file 2.json as my example).

Note) The official Google docs may be out-of-date (This is the case at the time of writing,), so I can offer this article about Room auto-migrations .