[英]RealmMigrationNeededException: Migration is required Realm, while adding new table on existing database, Android
I am using Realm gradle version "3.0.0", I have two table "Word" & "Favourite" like below我正在使用 Realm gradle 版本“3.0.0”,我有两个表“Word”和“Favorite”,如下所示
Now I want to add third Table named "History"现在我想添加名为“历史”的第三个表
for that i have done below code为此我做了下面的代码
@Override
public void migrate(DynamicRealm realm, long oldVersion, long newVersion) {
final RealmSchema schema = realm.getSchema();
if (oldVersion == 0) {
RealmObjectSchema wordSchema = schema.get("Word");
wordSchema.addField(DBHelper.COLUMN_NAME_PRONOUCE, String.class);
wordSchema.addField(DBHelper.COLUMN_NAME_TYPE, String.class);
oldVersion++;
} if(oldVersion == 1){
RealmObjectSchema favouriteSchema = schema.get("Favourite");
favouriteSchema.addField(DBHelper.COLUMN_NAME_ID, String.class);
favouriteSchema.addField(DBHelper.COLUMN_NAME_WORD, String.class);
favouriteSchema.addField(DBHelper.COLUMN_NAME_OBJECT_ID, String.class);
favouriteSchema.addField(DBHelper.COLUMN_NAME_PRONOUCE, String.class);
favouriteSchema.addField(DBHelper.COLUMN_NAME_TYPE, String.class);
favouriteSchema.addField(DBHelper.COLUMN_NAME_MEANING, String.class);
oldVersion++;
}
if(oldVersion == 2){
schema.create("History")
.addField(DBHelper.COLUMN_NAME_ID, String.class)
.addField(DBHelper.COLUMN_NAME_WORD, String.class)
.addField(DBHelper.COLUMN_NAME_OBJECT_ID, String.class)
.addField(DBHelper.COLUMN_NAME_PRONOUCE, String.class)
.addField(DBHelper.COLUMN_NAME_TYPE, String.class)
.addField(DBHelper.COLUMN_NAME_MEANING, String.class);
oldVersion++;
}
}
But I am getting below error,但我得到以下错误,
io.realm.exceptions.RealmMigrationNeededException: Migration is required due to the following errors:
- Property 'History.id' has been changed from 'string' to 'int'.
- Property 'History.word' has been made required.
- Property 'History.objectId' has been made required.
- Property 'History.pronunciation' has been made required.
- Property 'History.type' has been made required.
- Property 'History.meaning' has been made required.
I have not created any History table before, than why it is saying History.id has been changed from 'string' to 'int'?我之前没有创建任何历史表,为什么说 History.id 已从“字符串”更改为“整数”?
How to add History table properly?如何正确添加历史表?
if(oldVersion == 2){
schema.create("History")
.addField(DBHelper.COLUMN_NAME_ID, int.class)
.addField(DBHelper.COLUMN_NAME_WORD, String.class, FieldAttribute.REQUIRED)
.addField(DBHelper.COLUMN_NAME_OBJECT_ID, String.class, FieldAttribute.REQUIRED)
.addField(DBHelper.COLUMN_NAME_PRONOUCE, String.class, FieldAttribute.REQUIRED)
.addField(DBHelper.COLUMN_NAME_TYPE, String.class, FieldAttribute.REQUIRED)
.addField(DBHelper.COLUMN_NAME_MEANING, String.class, FieldAttribute.REQUIRED);
oldVersion++;
}
On your test phone, just uninstall/reinstall the app afterwards, or you'll need to bump the schema version and change the fields to the right type.在您的测试手机上,之后只需卸载/重新安装应用程序,或者您需要调整架构版本并将字段更改为正确的类型。
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