为什么无法通过房间迁移创建新表？

Question

我正在开发的应用程序需要能够从api下载一些“对象”以使其可以脱机使用，并且我正在使用带有sqlite的Room将其本地保存在设备上。 对于第一个表，我需要创建一个表，它可以毫无问题地工作，并且一切正常。 问题出在我创建第二张表时，由于某种原因我无法弄清该数据库迁移无法在数据库中创建。

我已经尝试过重新创建实体，清理架构，以便android studio重新创建json文件，但到目前为止没有成功。

实际上，带有架构的json文件已正确创建，但是当我尝试运行该应用程序时，出现以下异常之一：

08-06 15:07:18.558 3844-3844/br.com.neoedu.app E/AndroidRuntime: FATAL EXCEPTION: main
    Process: br.com.neoedu.app, PID: 3844
    java.lang.IllegalStateException: Migration didn't properly handle Resposta(br.com.neoedu.objeto.model.Resposta).
     Expected:
    TableInfo{name='Resposta', columns={correta=Column{name='correta', type='INTEGER', affinity='3', notNull=true, primaryKeyPosition=0}, questao=Column{name='questao', type='INTEGER', affinity='3', notNull=true, primaryKeyPosition=0}, resposta=Column{name='resposta', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0}, img_resposta=Column{name='img_resposta', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0}, id=Column{name='id', type='INTEGER', affinity='3', notNull=true, primaryKeyPosition=1}}, foreignKeys=[], indices=[]}
     Found:
    TableInfo{name='Resposta', columns={}, foreignKeys=[], indices=null}
        at br.com.neoedu.common.dao.AppDatabase_Impl$1.validateMigration(AppDatabase_Impl.java:109)
        at android.arch.persistence.room.RoomOpenHelper.onUpgrade(RoomOpenHelper.java:87)

这是一个实体，它的房间无法创建表并遵循模式json。

@Entity
public class Resposta implements RequestModel, Serializable {

    @Expose
    @SerializedName("id")
    @PrimaryKey
    private int id;

    @Expose
    @SerializedName("questao")
    @Ignore
    private Objeto questao;

    @ColumnInfo(name="questao")
    private int idQuestao;

    @Expose
    @SerializedName("resposta")
    @ColumnInfo(name = "resposta")
    private String resposta;

    @Expose
    @SerializedName("correta")
    @ColumnInfo(name = "correta")
    private boolean correta;

    @Expose
    @SerializedName("imgResposta")
    @ColumnInfo(name= "img_resposta")
    private String imgResposta;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public Objeto getQuestao() {
        return questao;
    }

    public void setQuestao(Objeto questao) {
        this.questao = questao;
    }

    public String getResposta() {
        return resposta;
    }

    public void setResposta(String resposta) {
        this.resposta = resposta;
    }

    public boolean isCorreta() {
        return correta;
    }

    public void setCorreta(boolean correta) {
        this.correta = correta;
    }

    public String getImgResposta() {
        return imgResposta;
    }

    public void setImgResposta(String imgResposta) {
        this.imgResposta = imgResposta;
    }

    public int getIdQuestao() {
        return idQuestao;
    }

    public void setIdQuestao(int idQuestao) {
        this.idQuestao = idQuestao;
    }```


Schema: 

```{
  "formatVersion": 1,
  "database": {
    "version": 2,
    "identityHash": "95d9e6cab68a655a3f82759ed5975ac3",
    "entities": [
      {
        "tableName": "Objeto",
        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER NOT NULL, `tipo` TEXT, `tipo_questao` INTEGER NOT NULL, `tri` TEXT, `titulo` TEXT, `descricao` TEXT, `conteudo` TEXT, `tipoConteudo` TEXT, `status` INTEGER NOT NULL, `link` TEXT, `fonte` TEXT, `data_criacao` INTEGER, `revisado_em` INTEGER, `exame` TEXT, `sub_exame` TEXT, `periodo_exame` TEXT, `ano` INTEGER NOT NULL, PRIMARY KEY(`id`))",
        "fields": [
          {
            "fieldPath": "id",
            "columnName": "id",
            "affinity": "INTEGER",
            "notNull": true
          },
          {
            "fieldPath": "tipo",
            "columnName": "tipo",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "tipoQuestao",
            "columnName": "tipo_questao",
            "affinity": "INTEGER",
            "notNull": true
          },
          {
            "fieldPath": "tri",
            "columnName": "tri",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "titulo",
            "columnName": "titulo",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "descricao",
            "columnName": "descricao",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "conteudo",
            "columnName": "conteudo",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "tipoConteudo",
            "columnName": "tipoConteudo",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "status",
            "columnName": "status",
            "affinity": "INTEGER",
            "notNull": true
          },
          {
            "fieldPath": "link",
            "columnName": "link",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "fonte",
            "columnName": "fonte",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "dataCriacao",
            "columnName": "data_criacao",
            "affinity": "INTEGER",
            "notNull": false
          },
          {
            "fieldPath": "revisadoEm",
            "columnName": "revisado_em",
            "affinity": "INTEGER",
            "notNull": false
          },
          {
            "fieldPath": "exame",
            "columnName": "exame",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "subExame",
            "columnName": "sub_exame",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "periodoExame",
            "columnName": "periodo_exame",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "ano",
            "columnName": "ano",
            "affinity": "INTEGER",
            "notNull": true
          }
        ],
        "primaryKey": {
          "columnNames": [
            "id"
          ],
          "autoGenerate": false
        },
        "indices": [],
        "foreignKeys": []
      },
      {
        "tableName": "Resposta",
        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER NOT NULL, `questao` INTEGER NOT NULL, `resposta` TEXT, `correta` INTEGER NOT NULL, `img_resposta` TEXT, PRIMARY KEY(`id`))",
        "fields": [
          {
            "fieldPath": "id",
            "columnName": "id",
            "affinity": "INTEGER",
            "notNull": true
          },
          {
            "fieldPath": "idQuestao",
            "columnName": "questao",
            "affinity": "INTEGER",
            "notNull": true
          },
          {
            "fieldPath": "resposta",
            "columnName": "resposta",
            "affinity": "TEXT",
            "notNull": false
          },
          {
            "fieldPath": "correta",
            "columnName": "correta",
            "affinity": "INTEGER",
            "notNull": true
          },
          {
            "fieldPath": "imgResposta",
            "columnName": "img_resposta",
            "affinity": "TEXT",
            "notNull": false
          }
        ],
        "primaryKey": {
          "columnNames": [
            "id"
          ],
          "autoGenerate": false
        },
        "indices": [],
        "foreignKeys": []
      }
    ],
    "setupQueries": [
      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, \"95d9e6cab68a655a3f82759ed5975ac3\")"
    ]
  }
}

数据库类：

@Database(entities = {Objeto.class, Resposta.class}, version = 2)
@TypeConverters({DateConverter.class, QuestaoConverter.class})
public abstract class AppDatabase extends RoomDatabase {

    private static final String DB_NAME = "neoedu.db";
    private static volatile AppDatabase instance;

    //private AppDatabase(){}

    private static final Migration MIGRATION_1_2 = new Migration(1, 2) {
        @Override
        public void migrate(SupportSQLiteDatabase database) {
            // Since we didn't alter the table, there's nothing else to do here.
        }
    };

    public synchronized static AppDatabase getInstance(Context context){
        if(null == instance) {
            instance = create(context);
        }
        return instance;
    }

    private static AppDatabase create(Context context) {
        return Room.databaseBuilder(
                context,
                AppDatabase.class,
                DB_NAME
            )
                .addMigrations(MIGRATION_1_2)
                .allowMainThreadQueries()
                .build();
    }


    public abstract ObjetoDAO getObjetoDao();
    public abstract RespostaDAO getRespostaDao();
}

我想念什么？