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Android ORM框架介绍之android-liteorm注解与封装

LiteOrm

代号: archiver

LiteOrm 是一个速度快、小巧却强大的 Android ORM 框架类库，速度快、体积小、性能高，开发者基本一行代码实现数据库的增删改查操作，以及实体关系的持久化和自动映射。 自动化且比系统自带数据库操作快1倍！

作者个人主页

liteorm注解

常用注解

• @Table：用于类，默认使用类名，也可以自定义。如：
  
  @Table(“tb_user”)
  
• @PrimaryKey：主键，通过AssignType枚举来设置值，如：
  
  @PrimaryKey(AssignType.AUTO_INCREMENT)
  
  
  • BY_MYSELF,
  • AUTO_INCREMENT;//自增
• @Unique：唯一字段（行）
• @UniqueCombine：唯一（列中字段值唯一）
• @NotNull：字段部位none
• @Ingore：使用该注解表示字段不存入数据库
• @Mapping：表示关联关系，通过枚举Relation设置值，如：
  
  @Mapping(Relation.OneToOne)
  
  
  • ManyToMany,//多对多
  • OneToMany,//一对多
  • ManyToOne,//多对一
  • OneToOne;//一对一
• @Column：自定义字段名(列名)。如：
  
  @Column(“name”)
  
• @Conflict：数据库冲突策略，通过枚举Strategy设置值，可用于表，也可用于字段上
  
  • ROLLBACK(” ROLLBACK “),//回滚
  • ABORT(” ABORT “),//中断
  • FAIL(” FAIL “),//失败
  • IGNORE(” IGNORE “),//忽略
  • REPLACE(” REPLACE “);//替换

liteorm的封装

public class DataBaseManager {
    private static DataBaseManager manager;
    private static final String DB_NAME = "my.db";
    private LiteOrm liteOrm;

    private DataBaseManager(Context context) {
        if (liteOrm == null) {
            liteOrm = LiteOrm.newSingleInstance(context, DB_NAME);
        }
    }

    public static DataBaseManager getInstance(Context context) {
        context = context.getApplicationContext();
        if (manager == null) {
            synchronized (DataBaseManager.class) {
                if (manager == null) {
                    manager = new DataBaseManager(context);
                }
            }
        }
        return manager;
    }

    /**
     * 插入一条记录
     */
    public <T> long insert(T t) {
        return liteOrm.save(t);
    }

    /**
     * 插入所有记录
     */
    public <T> void insertAll(List<T> list) {
        liteOrm.save(list);
    }

    /**
     * 根据对象查询数据
     */
    public <T> int update(T t) {
        return liteOrm.update(t);
    }

    /**
     * 查询所有数据
     */
    public <T> int updateAll(List<T> list) {
        return liteOrm.update(list);
    }

    /**
     * 根据id查询
     */
    public <T> T query(long id, Class<T> clazz) {
        return liteOrm.queryById(id, clazz);
    }

    /**
     * 查询所有
     */
    public <T> List<T> queryAll(Class<T> cla) {
        return liteOrm.query(cla);
    }

    /**
     * 查询  某字段 等于 Value的值
     */
    @SuppressWarnings("unchecked")
    public <T> List<T> queryByWhere(Class<T> cla, String field, String[] value) {
        return liteOrm.query(new QueryBuilder(cla).where(field + "=?", value));
    }

    /**
     * 查询  某字段 等于 Value的值  可以指定从1-20，就是分页
     */
    @SuppressWarnings("unchecked")
    public <T> List<T> queryByWhereLength(Class<T> cla, String field, String[] value, int start, int length) {
        return liteOrm.query(new QueryBuilder(cla).where(field + "=?", value).limit(start, length));
    }

    /**
     * 删除一个数据
     */
    public <T> void delete(T t) {
        liteOrm.delete(t);
    }

    /**
     * 删除所有数据
     */
    public <T> void deleteAll(Class<T> clazz) {
        liteOrm.deleteAll(clazz);
    }

    /**
     * 删除集合中的数据
     */
    public <T> void deleteList(List<T> list) {
        liteOrm.delete(list);
    }

    /**
     * 删除数据库
     */
    public void deleteDatabase() {
        liteOrm.deleteDatabase();
    }
}

liteorm的使用

@Table("tb_user")
public class User {
    @PrimaryKey(AssignType.AUTO_INCREMENT)//主键，自增
    private long id;
    @NotNull
    private String name;
    private int age;

    public User(){}
    public User(long id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

MainActivity

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button insert;
    private Button update;
    private Button query;
    private Button queryAll;
    private Button delete;
    private Button deleteAll;
    private TextView tv_query;
    private TextView tv_queryall;
    private DataBaseManager manager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        insert = (Button) findViewById(R.id.btn1);
        update = (Button) findViewById(R.id.btn2);
        query = (Button) findViewById(R.id.btn3);
        queryAll = (Button) findViewById(R.id.btn4);
        delete = (Button) findViewById(R.id.btn5);
        deleteAll = (Button) findViewById(R.id.btn6);

        tv_query = (TextView) findViewById(R.id.tv_query);
        tv_queryall = (TextView) findViewById(R.id.tv_queryall);

        insert.setOnClickListener(this);
        update.setOnClickListener(this);
        query.setOnClickListener(this);
        queryAll.setOnClickListener(this);
        delete.setOnClickListener(this);
        deleteAll.setOnClickListener(this);

        manager = DataBaseManager.getInstance(MainActivity.this);
    }

    private void deleteAll() {
        manager.deleteAll(User.class);
    }

    private void deleteData() {
        User user = new User();
        user.setId(1);
        manager.delete(user);
    }

    private List<User> queryAll() {
        return manager.queryAll(User.class);
    }

    private User queryData() {
        return manager.query(1, User.class);
    }

    private void updateData() {
        User user = new User(1, "lisi", 28);
        manager.update(user);
    }

    private void insertData() {
        User user1 = new User(1, "zhangsan", 20);
        manager.insert(user1);
        User user2 = new User(2, "zhangsan", 20);
        manager.insert(user2);
        User user3 = new User(3, "zhangsan", 20);
        manager.insert(user3);
        User user4 = new User(4, "zhangsan", 20);
        manager.insert(user4);

        //inserAll
//        List<User> list = new ArrayList<>();
//        list.add(user1);
//        list.add(user2);
//        list.add(user3);
//        list.add(user4);
//        manager.insertAll(list);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn1:
                insertData();
                break;
            case R.id.btn2:
                updateData();
                break;
            case R.id.btn3:
                User user = queryData();
                if (user == null) {
                    tv_query.setText("查询的数据不存在");
                } else {
                    tv_query.setText(user.toString());
                }
                break;
            case R.id.btn4:
                List<User> list = queryAll();
                if (list == null) {
                    tv_queryall.setText("查询的数据不存在");
                } else {
                    tv_queryall.setText(list.toString());
                }
                break;
            case R.id.btn5:
                deleteData();
                break;
            case R.id.btn6:
                deleteAll();
                break;
        }
    }
}