Android 开源数据库框架 - LitePal 的使用

   <h2>简介</h2>    <p>LitePal是一款开源的Android数据库框架，采用了关系映射的模式。LitePal在github上的项目地址： <a href="/misc/goto?guid=4959746370674825430" rel="nofollow,noindex">https://github.com/LitePalFramework/LitePal</a></p>    <h2>配置LitePal</h2>    <pre>  <code class="language-xml">dependencies {   ....   compile 'org.litepal.android:core:1.5.1'  }</code></pre>    <p>在app/src/main 目录下新建目录assets，在assets目录下建litepal.xml 文件</p>    <pre>  <code class="language-xml"><?xml version="1.0" encoding="utf-8"?>  <litepal>      <dbname value="Person" ></dbname>        <version value="1" ></version>        <list>          <mapping class="com.zhoujian.litepal.bean.Person"></mapping>      </list>  </litepal></code></pre>    <p>标签用于指定数据库名</p>    <p>标签用于指定版本号</p>    <p>标签用于指定所有的映射模型</p>    <p>在清单文件中配置LitePalApplication</p>    <pre>  <code class="language-xml"><application          android:name="org.litepal.LitePalApplication"          android:allowBackup="true"          android:icon="@mipmap/ic_launcher"          android:label="@string/app_name"          android:roundIcon="@mipmap/ic_launcher_round"          android:supportsRtl="true"          android:theme="@style/AppTheme">          <activity android:name=".activity.MainActivity">              <intent-filter>                  <action android:name="android.intent.action.MAIN"/>                    <category android:name="android.intent.category.LAUNCHER"/>              </intent-filter>          </activity>      </application></code></pre>    <h2>实战</h2>    <p>创建JavaBean</p>    <p>Person.java</p>    <pre>  <code class="language-java">package com.zhoujian.litepal.bean;    import org.litepal.crud.DataSupport;    /**   * Created by zhoujian on 2017/3/29.   */    public class Person extends DataSupport  {      private String name;        private int age;        private int id;        private String weight;        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;      }        public String getWeight() {          return weight;      }        public void setWeight(String weight) {          this.weight = weight;      }        public int getId() {          return id;      }        public void setId(int id) {          this.id = id;      }  }</code></pre>    <p>增删改查数据库</p>    <p>MainActivity.java</p>    <pre>  <code class="language-java">package com.zhoujian.litepal.activity;    import android.os.Bundle;  import android.support.v7.app.AppCompatActivity;  import android.util.Log;  import android.view.View;  import android.widget.Button;  import android.widget.Toast;  import com.zhoujian.litepal.R;  import com.zhoujian.litepal.bean.Person;  import org.litepal.crud.DataSupport;  import org.litepal.tablemanager.Connector;  import java.util.List;    public class MainActivity extends AppCompatActivity  {        private Button mCreateDatabase;      private Button mAddData;      private Button mUpdateData;      private Button mDeleteButton;      private Button mQueryButton;        @Override      protected void onCreate(Bundle savedInstanceState)      {          super.onCreate(savedInstanceState);          setContentView(R.layout.activity_main);          initViews();            clickEvents();      }          private void initViews()      {          mCreateDatabase = (Button) findViewById(R.id.create_database);          mAddData = (Button) findViewById(R.id.add_data);          mUpdateData = (Button) findViewById(R.id.update_data);          mDeleteButton = (Button) findViewById(R.id.delete_data);          mQueryButton = (Button) findViewById(R.id.query_data);      }        private void clickEvents()      {          mCreateDatabase.setOnClickListener(new View.OnClickListener() {              @Override              public void onClick(View v) {                  //创建数据库                  Connector.getDatabase();              }          });              mAddData.setOnClickListener(new View.OnClickListener() {              @Override              public void onClick(View v) {                    Person person = new Person();                  person.setId(1);                  person.setName("周润发");                  person.setAge(62);                  person.setWeight("80kg");                  person.save();                    person.clearSavedState();                  person.setId(2);                  person.setName("周杰伦");                  person.setAge(45);                  person.setWeight("65kg");                  person.save();                    person.clearSavedState();                  person.setId(3);                  person.setName("周星驰");                  person.setAge(65);                  person.setWeight("70kg");                  person.save();                    Toast.makeText(MainActivity.this, "添加数据成功", Toast.LENGTH_SHORT).show();              }          });            mUpdateData.setOnClickListener(new View.OnClickListener()          {              @Override              public void onClick(View v) {                  Person person = new Person();                    //把id = 3 的那个人 姓名更改为周建  年龄改为28   体重改为62kg                  person.setName("周建");                  person.setAge(28);                  person.setWeight("62kg");                  person.updateAll("id = ?", "3");                    Toast.makeText(MainActivity.this, "更新数据成功", Toast.LENGTH_SHORT).show();                }          });            mDeleteButton.setOnClickListener(new View.OnClickListener() {              @Override              public void onClick(View v)              {                  //删除年龄大于60的人                  DataSupport.deleteAll(Person.class, "age > ?", "60");                  Toast.makeText(MainActivity.this, "删除数据成功", Toast.LENGTH_SHORT).show();              }          });                mQueryButton.setOnClickListener(new View.OnClickListener() {              @Override              public void onClick(View v)              {                  List<Person> persons = DataSupport.findAll(Person.class);                  for (Person person: persons) {                      Log.d("MainActivity", "person name is " + person.getName());                      Log.d("MainActivity", "person weight is " + person.getWeight());                      Log.d("MainActivity", "person age is " + person.getAge());                      Log.d("MainActivity", "person id is " + person.getId());                  }                    Toast.makeText(MainActivity.this, "查询数据成功", Toast.LENGTH_SHORT).show();              }          });        }  }</code></pre>    <p>  </p>   <p>来自：https://juejin.im/post/58db82b35c497d00571308b8</p>    <p></p>    <p> </p>