45 lines
1.6 KiB
Java
45 lines
1.6 KiB
Java
package com.example.myapplication.DataBase;
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import android.content.Context;
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import androidx.annotation.NonNull;
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import androidx.room.Database;
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import androidx.room.Room;
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import androidx.room.RoomDatabase;
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import androidx.room.migration.Migration;
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import androidx.sqlite.db.SupportSQLiteDatabase;
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import com.example.myapplication.model.AudioEntity;
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import com.example.myapplication.model.ImageEntity;
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import com.example.myapplication.model.Turbine;
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@Database(entities = {ImageEntity.class, Turbine.class, AudioEntity.class}, version = 4) // 版本号增加，添加新实体
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public abstract class AppDatabase extends RoomDatabase {
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public abstract ImageDao imageDao();
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public abstract TurbineDao turbineDao(); // 添加新的DAO
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public abstract AudioDao AudioDao();
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private static volatile AppDatabase INSTANCE;
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private static final Migration MIGRATION_4_5 = new Migration(4, 5) {
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@Override
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public void migrate(@NonNull SupportSQLiteDatabase database) {
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}
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};
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public static AppDatabase getDatabase(Context context) {
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if (INSTANCE == null) {
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synchronized (AppDatabase.class) {
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if (INSTANCE == null) {
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INSTANCE = Room.databaseBuilder(context.getApplicationContext(),
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AppDatabase.class, "app_database")
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.fallbackToDestructiveMigration() // 简单处理，正式项目应该实现Migration
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.build();
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}
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}
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}
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return INSTANCE;
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}
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} |