Androrm - Android的ORM框架 - Androrm

Androrm 是 Android 平臺上的一個對象關系映射框架，也就是我們常說的 ORM 框架。用于幫助你快速開發使用數據庫的應用，封裝了常用的表創建、對象讀寫和查詢，通過將 Model 類映射到數據庫表，直接對對象進行操作便可讀寫數據庫。

下面我們給出一個簡單的使用 Androrm 的教程：

1. 創建 Model 類

public class Book extends Model {

    // fields visibility is set to protected,
    // so the Model class can access it
    protected CharField mTitle;

    // zero-argument constructor, that can be called
    // by androrm, to gather field information
    public Book() {
        super();

        // set up field with maxLength parameter
        mTitle = new CharField(80);
    }

    public getTitle() {
        return mTitle.get();
    }

}

public class Author extends Model {

    protected CharField mName;

    public Author() {
        super();

        mName = new CharField(80);
    }

    public void getName() {
         return mName.get();
    }

    public void setName(String name) {
         mName.set(name);
    }

}

2. 創建數據庫

接下來我們需要在應用的 onCreate 方法中創建數據庫

List<Class<? extends Model>> models = new ArrayList<Class<? extends Model>>();
models.add(Author.class);
models.add(Book.class);                                                     

DatabaseAdapter.setDatabaseName("a_database_name");
DatabaseAdapter adapter = new DatabaseAdapter(getApplicationContext());
adapter.setModels(models);

3. 創建表關系

Androrm 有一個特殊的數據域——ForeignKeyField，通過它來定義外鍵關聯

public class Book extends Model {

    // fields visibility is set to protected,
    // so the Model class can access it
    protected CharField mTitle;

    // Link the Author model to the Book model.
    protected ForeignKeyField<Author> mAuthor;

    // zero-argument constructor, that can be called
    // by androrm, to gather field information
    public Book() {
        super();

        // set up field with maxLength parameter
        mTitle = new CharField(80);

        // initialize the foreign key relation
        mAuthor = new ForeignKeyField<Author>(Author.class);
    }

    public String getTitle() {
        return mTitle.get();
    }

   public void setAuthor(Author author) {
        mAuthor.set(author);
   }

}

4. 插入數據

// In your activity

Author author = new Author();
author.setName("My Author");
author.save(this);

Book book = new Book();
book.setName("Book name");
book.setAuthor(author);
book.save(this);

到此，整個簡單的教程到此結束，更詳細的關于 Androrm 的使用方法請參考文檔。