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GreenDaoUpgradeHelper是一个greenDao的数据库升级帮助类。使用它可以很容易解决数据库升级问题,只需一行代码。
原始代码来自stackoverflow。
1.在根目录的build.gradle文件的repositories内添加如下代码:
allprojects {
repositories {
...
maven { url "https://jitpack.io" }
}
}
2.添加依赖(greendao 3.0及以上)
dependencies {
compile 'org.greenrobot:greendao:3.2.0'
compile 'io.github.yuweiguocn:GreenDaoUpgradeHelper:v2.2.1'
}
如果你使用的greendao是3.0以前的版本,请使用下面的依赖:
dependencies {
compile 'de.greenrobot:greendao:2.0.0'
compile 'com.github.yuweiguocn:GreenDaoUpgradeHelper:v1.0.1'
}
3.添加一个新类继承DaoMaster.OpenHelper,添加构造函数并实现onUpgrade方法,在onUpgrade方法添加如下代码即可,参数为所有的Dao类:
MigrationHelper.migrate(db, new MigrationHelper.ReCreateAllTableListener() {
@Override
public void onCreateAllTables(Database db, boolean ifNotExists) {
DaoMaster.createAllTables(db, ifNotExists);
}
@Override
public void onDropAllTables(Database db, boolean ifExists) {
DaoMaster.dropAllTables(db, ifExists);
}
},TestDataDao.class, TestData2Dao.class, TestData3Dao.class);
完整代码:
public class MySQLiteOpenHelper extends DaoMaster.OpenHelper {
public MySQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory) {
super(context, name, factory);
}
@Override
public void onUpgrade(Database db, int oldVersion, int newVersion) {
MigrationHelper.migrate(db, new MigrationHelper.ReCreateAllTableListener() {
@Override
public void onCreateAllTables(Database db, boolean ifNotExists) {
DaoMaster.createAllTables(db, ifNotExists);
}
@Override
public void onDropAllTables(Database db, boolean ifExists) {
DaoMaster.dropAllTables(db, ifExists);
}
},TestDataDao.class, TestData2Dao.class, TestData3Dao.class);
}
}
4.初始化
//MigrationHelper.DEBUG = true; //如果你想查看日志信息,请将DEBUG设置为true
MySQLiteOpenHelper helper = new MySQLiteOpenHelper(this, "test.db",
null);
daoMaster = new DaoMaster(helper.getWritableDatabase());
-keepclassmembers class * extends org.greenrobot.greendao.AbstractDao {
public static void dropTable(org.greenrobot.greendao.database.Database, boolean);
public static void createTable(org.greenrobot.greendao.database.Database, boolean);
}
weibo:@于卫国
gmail:yuweiguocn@gmail.com
Copyright 2016 yuweiguocn
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
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