litepal开源数据库工具

首先添加如下依赖

compile 'org.litepal.android:core:1.6.0'

新建assets文件夹，然后在文件夹中添加litepal.xml文件，如下图所示

s.png

litepal.xml文件中，内容如下：

<?xml version="1.0" encoding="utf-8"?>
<litepal>
    <dbname value="book"/>数据库名称
    <version value="1"/>数据库版本
    <list>
        <mapping class="com.example.liang.lianxi.Book"/>
    </list>
</litepal>

修改androidmanifest中的application的name属性。如下所示：

<application
        android:name="org.litepal.LitePalApplication"
        ...

Book文件中

public class Book extends DataSupport{
    private int id;
    private String author;
    private double price;
    private int pages;
    private String name;

    public int getId() {
        return id;
    }

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

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public int getPages() {
        return pages;
    }

    public void setPages(int pages) {
        this.pages = pages;
    }

    public String getName() {
        return name;
    }

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

Mainactivity文件中

public class MainActivity extends AppCompatActivity {
    private Button button;
    private Button button1;
    private Button button2;
    private Button button3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Connector.getDatabase();
        setContentView(R.layout.activity_main);
        button = (Button) findViewById(R.id.button);
        button1 = (Button) findViewById(R.id.button1);
        button2= (Button) findViewById(R.id.button2);
        button3 = (Button) findViewById(R.id.button3);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Book book = new Book();
                book.setName("老人与海");
                book.setAuthor("海明威");
                book.setPages(444);
                book.setPrice(20.0);
                book.save();
            }
        });
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Book book=new Book();
                book.setPrice(30.0);
                book.updateAll("name='老人与海'");
            }
        });
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DataSupport.deleteAll(Book.class,"name='老人与海'");
            }
        });
        button3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                List<Book>list=DataSupport.findAll(Book.class);
                for(Book book:list){
                    Log.i("xinxi",book.getName()+","+book.getAuthor()+","+book.getPages()+","+book.getPrice());
                }
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:text="增加数据"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button" />
    <Button
        android:text="更新数据"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button1" />
    <Button
        android:text="删除数据"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button2" />
    <Button
        android:text="查询数据"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button3" />
</LinearLayout>

device-2017-11-12-202612.png