Database storage-Mobile Platform as a Service(mPaaS)-阿里云帮助中心

The mPaaS database storage feature is based on the OrmLite framework and provides underlying database encryption. You can use the following interfaces to create, delete, update, and query data:

For baseline 10.2.3 and later: com.alibaba.j256.ormlite.dao.Dao
For baseline 10.1.68 and earlier: com.j256.ormlite.dao.Dao

Note

Do not directly encrypt an existing database. This will cause a crash in the native layer during decryption. Instead, create a new encrypted database and copy the content from the original database into it.

Generate a data table

// The database table name. The class name is used by default.
@DatabaseTable
public class User {
    // Primary key
    @DatabaseField(generatedId = true)
    public int id;
    // The name field must be unique.
    @DatabaseField(unique = true)
    public String name;
    @DatabaseField
    public int color;
    @DatabaseField
    public long timestamp;
}

Create an OrmLiteSqliteOpenHelper

You can create a custom DemoOrmLiteSqliteOpenHelper class that inherits from OrmLiteSqliteOpenHelper and use it to create and encrypt a database.

For baseline 10.2.3 and later:

public class DemoOrmLiteSqliteOpenHelper extends OrmLiteSqliteOpenHelper {

    /**
     * Database name
     */
    private static final String DB_NAME = "com_mpaas_demo_storage.db";

    /**
     * Current database version
     */
    private static final int DB_VERSION = 1;

    /**
     * The database encryption key. mPaaS supports database encryption to make data on the device more secure. If this is null, the database is not encrypted.
     * Note: The password can only be set once. No API is provided to change the password. You cannot set a password for an unencrypted database to encrypt it. This will cause a crash.
     */
    private static final String DB_PASSWORD = "mpaas";

    public DemoOrmLiteSqliteOpenHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
        setPassword(DB_PASSWORD);
    }

    /**
     * The callback function for when the database is created.
     *
     * @param sqLiteDatabase   The database
     * @param connectionSource The connection
     */
    @Override
    public void onCreate(MPSQLiteDatabase sqLiteDatabase, ConnectionSource connectionSource) {
        try {
            // Create the User table
            TableUtils.createTableIfNotExists(connectionSource, User.class);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    /**
     * The callback function for when the database is updated.
     *
     * @param database         The database
     * @param connectionSource The connection
     * @param oldVersion       The old database version
     * @param newVersion       The new database version
     */
    @Override
    public void onUpgrade(MPSQLiteDatabase database, ConnectionSource connectionSource, int oldVersion, int newVersion) {
        try {
            // Delete the old User table and ignore errors
            TableUtils.dropTable(connectionSource, User.class, true);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            // Recreate the User table
            TableUtils.createTableIfNotExists(connectionSource, User.class);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

For baseline 10.1.68 and earlier:

public class DemoOrmLiteSqliteOpenHelper extends OrmLiteSqliteOpenHelper {

    /**
     * Database name
     */
    private static final String DB_NAME = "com_mpaas_demo_storage.db";

    /**
     * Current database version
     */
    private static final int DB_VERSION = 1;

    /**
     * The database encryption key. mPaaS supports database encryption to make data on the device more secure. If this is null, the database is not encrypted.
     * Note: The password can only be set once. No API is provided to change the password. You cannot set a password for an unencrypted database to encrypt it. This will cause a crash.
     */
    private static final String DB_PASSWORD = "mpaas";

    public DemoOrmLiteSqliteOpenHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
        setPassword(DB_PASSWORD);
    }

    /**
     * The callback function for when the database is created.
     *
     * @param sqLiteDatabase   The database
     * @param connectionSource The connection
     */
    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase, ConnectionSource connectionSource) {
        try {
            // Create the User table
            TableUtils.createTableIfNotExists(connectionSource, User.class);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    /**
     * The callback function for when the database is updated.
     *
     * @param database         The database
     * @param connectionSource The connection
     * @param oldVersion       The old database version
     * @param newVersion       The new database version
     */
    @Override
    public void onUpgrade(SQLiteDatabase database, ConnectionSource connectionSource, int oldVersion, int newVersion) {
        try {
            // Delete the old User table and ignore errors
            TableUtils.dropTable(connectionSource, User.class, true);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            // Recreate the User table
            TableUtils.createTableIfNotExists(connectionSource, User.class);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Query data

This example queries all data from the User table and sorts it in ascending order by the timestamp field.

    /**
     * Initialize DB data
     */
    private void initData() {
        mData.clear();
        try {
            mData.addAll(mDbHelper.getDao(User.class).queryBuilder().orderBy("timestamp", true).query());
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

Insert data

    /**
     * Insert user information
     *
     * @param user The user information
     */
    private void insertUser(User user) {
        if (null == user) {
            return;
        }
        try {
            // mDbHelper = new DemoOrmLiteSqliteOpenHelper(this); For more information, see Create an OrmLiteSqliteOpenHelper above.
            mDbHelper.getDao(User.class).create(user);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

Delete data

    /**
     * Delete user information
     *
     * @param user The user information
     */
    private void deleteUser(User user) {
        try {
            // mDbHelper = new DemoOrmLiteSqliteOpenHelper(this); For more information, see Create an OrmLiteSqliteOpenHelper above.
            mDbHelper.getDao(User.class).delete(user);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }