在安卓开发中,如何用Ormlite框架实现CRUD操作,并且给出实现代码
时间: 2023-02-21 20:37:11 浏览: 61
Ormlite是一个用于Android开发的对象关系映射(ORM)框架,它可以将数据库中的数据映射到Java对象,从而使开发者不需要编写复杂的SQL语句来操作数据库。
要在Ormlite框架中实现CRUD操作,需要以下几步:
1. 在项目中添加Ormlite的依赖:
```
implementation 'com.j256.ormlite:ormlite-core:5.0'
implementation 'com.j256.ormlite:ormlite-android:5.0'
```
2. 定义Java对象,使用@DatabaseTable注解将其映射到数据库表:
```
@DatabaseTable(tableName = "person")
public class Person {
@DatabaseField(generatedId = true)
private int id;
@DatabaseField(columnName = "name")
private String name;
@DatabaseField(columnName = "age")
private int age;
// 省略getter和setter方法
}
```
3. 创建数据库,使用OrmLiteSqliteOpenHelper类创建数据库:
```
public class DatabaseHelper extends OrmLiteSqliteOpenHelper {
private static final String DATABASE_NAME = "person.db";
private static final int DATABASE_VERSION = 1;
private Dao<Person, Integer> personDao;
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase database, ConnectionSource connectionSource) {
try {
TableUtils.createTable(connectionSource, Person.class);
} catch (SQLException e) {
e.printStackTrace();
}
}
@Override
public void onUpgrade(SQLiteDatabase database, ConnectionSource connectionSource, int oldVersion, int newVersion) {
try {
TableUtils.dropTable(connectionSource, Person.class, true);
onCreate(database, connectionSource);
} catch (SQLException e) {
e.printStackTrace();
}
}
public Dao<Person, Integer> getPersonDao() throws SQLException {
if (personDao == null) {
personDao = getDao(Person.class);
}
return personDao;