使用前需要在app/build.gradle文件中添加如下内容：
compile 'org.litepal.android:core:1.4.1'
右键app/src/main新建assets目录，右键该目录，新建litepal.xml：
<?xml version="1.0" encoding="utf-8" ?><litepal><dbname value="BookStore"></dbname><version value="1"></version><list></list></litepal>
在AndroidMainfest中的<application>标签添加下面属性：
android:name="org.litepal.LitePalApplication"
<applicationandroid:name="org.litepal.LitePalApplication"android:allowBackup="true"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"android:supportsRtl="true"android:theme="@style/AppTheme"><activity android:name=".MainActivity"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity></application>
创建Book类：
public class Book {private int id;private String author;private double price;private int pages;private String name;public String getAuthor() {return author;}public int getId() {return id;}public String getName() {return name;}public int getPages() {return pages;}public double getPrice() {return price;}public void setAuthor(String author) {this.author = author;}public void setId(int id) {this.id = id;}public void setName(String name) {this.name = name;}public void setPages(int pages) {this.pages = pages;}public void setPrice(double price) {this.price = price;}}
然后在litepal.xml中增加一行代码，使其映射到Book类：
<?xml version="1.0" encoding="utf-8" ?><litepal><dbname value="BookStore"></dbname><version value="1"></version><list><mapping class="top.xiexiaodong.litepaldemo.Book"></mapping></list></litepal>
之后在映射类，在<list>标签中继续加上就行。
<?xml version="1.0" encoding="utf-8" ?><litepal><dbname value="BookStore"></dbname><version value="1"></version><list><mapping class="top.xiexiaodong.litepaldemo.Book"></mapping><mapping class="top.xiexiaodong.litepaldemo.Category"></mapping></list></litepal>
它不用先drop在创建，会保存之前的数据。
简单的增删改查：
public class MainActivity extends AppCompatActivity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button createButton = (Button) findViewById(R.id.create_button);createButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {LitePal.getDatabase();}});Button insertButton = (Button) findViewById(R.id.insert_button);insertButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Book book = new Book();book.setName("name 1");book.setAuthor("zh2的");book.setPages(133);book.setPrice(123.3);book.setPress("Unkonw");book.save();}});// 不能对已经存在的数据进行修改Button updateButton = (Button) findViewById(R.id.update_button);updateButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Book book = new Book();book.setName("name 2");book.setAuthor("zh3的");book.setPages(143);book.setPrice(143.3);book.setPress("Unkonw 2");book.save();book.setPrice(11.11);book.save();}});// 不能设置字段的新值为默认值，int=0等，可以通过book.setToDefaut("pages");方法将pages字段设置成默认值Button update2Button = (Button) findViewById(R.id.update2_button);update2Button.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Book book = new Book();book.setPrice(324.1);book.setPress("Unkonw 3");book.updateAll("name = ? and author = ?", "name 2", "zh3的");}});Button deleteButton = (Button) findViewById(R.id.delete_button);deleteButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {DataSupport.deleteAll(Book.class, "price < ?", "15");}});Button selectButton = (Button) findViewById(R.id.select_button);selectButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {List<Book> books = DataSupport.findAll(Book.class);for (Book book : books) {Log.d("xxd", book.getName() + book.getAuthor() + book.getPages() + book.getPrice() + book.getPress());}}});}}
查询第一条数据：
Book firstBook = DataSupport.findFirst(Book.class);
查询最后一条语句：
Book lastBook = DataSupport.findLast(Book.class);
-
select()方法用于指定查询那几列数据。
List<Book> books = DataSupport.select("name", "author").find(Book.class);
-
where()方法用于指定查询的约束条件。
List<Book> books = DataSupport.where("pages > ?", "300").find(Book.class);
-
order()方法用于指定结果的排列方式。
List<Book> books = DataSupport.order("price desc").find(Book.class);
-
limit()方法用于指定查询结果的数量。
List<Book> books = DataSupport.limit(3).find(Book.class);
-
offset()方法用于指定查询结果的偏移量。
List<Book> books = DataSupport.limit(3).offset(1).find(Book.class);
- limit(3)表示前3个数据，offset(1)偏移1后结果变成第2，3，4个数据了。
以上方法任意组合。如果特殊需求，可用原生SQL：
Cursor c = DataSupport.findBySQL("select * from Book where pages > ? and price < ?", "300", "20");
findBySQL()原生查询。