更快捷操作数据库 LitePal

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更快捷操作数据库 LitePal_Mr_Leixiansheng的博客-CSDN博客

作用：LitePal使数据库操作更加快捷方便

步骤：

1、引入LitePal依赖，在Gradle(app)–>dependencies 中引入依赖：implementation ‘org.litepal.android:java:3.0.0’

并在AndroidManifest.xml–>application 中添加：android:name=”org.litepal.LitePalApplication”

2、AS app 下创建 assets 文件夹，新建 litepal.xml 文件。并配置好dbname、version、list

3、新建类：作为表格。设置好set、get。在1中list引入此类

4、在主活动中进行库创建和数据的增删改查

代码如下：

1、引入依赖、环境搭建

dependencies {
    implementation 'org.litepal.android:java:3.0.0'
}

manifest下添加或在 Application中初始化

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

LitePal.initialize(this);

2、package模式下，在app–>main下创建 assets 文件夹，新建 litepal.xml 文件（litepal.xml需要手动移动到assets文件夹下）

<?xml version="1.0" encoding="utf-8"?>
<litepal>
    <dbname value="bookstore" ></dbname>

    <version value="1"></version>

    <list>
        <mapping class="com.leixiansheng.litepaltest.Book"></mapping>
        <mapping class="com.leixiansheng.litepaltest.Category"></mapping>
    </list>
</litepal>

3、创建表格类

package com.leixiansheng.litepaltest;

import org.litepal.crud.DataSupport;

/**
 * Created by Leixiansheng on 2017/8/14.
 */

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

    public String getPress() {
        return press;
    }

    public void setPress(String press) {
        this.press = press;
    }

    public String getAuthor() {
        return author;
    }

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

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public int getPages() {
        return pages;
    }

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

    public double getPrice() {
        return price;
    }

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

package com.leixiansheng.litepaltest;

import org.litepal.crud.DataSupport;

/**
 * Created by Leixiansheng on 2017/8/14.
 */

public class Category extends LitePalSupport {
    private int id;
    private int categoryCode;

    public int getCategoryCode() {
        return categoryCode;
    }

    public void setCategoryCode(int categoryCode) {
        this.categoryCode = categoryCode;
    }

    public int getId() {
        return id;
    }

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

3、主活动使用LitePal进行数据库操作

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.leixiansheng.litepaltest.MainActivity"
    android:orientation="vertical">

    <Button
        android:id="@+id/create_db"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Create db"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/add_db"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Add db"
        android:textAllCaps="false"/>

       <Button
        android:id="@+id/update_db"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Update db"
        android:textAllCaps="false"/>

     <Button
        android:id="@+id/update2_db"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Update2 db"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/delete_db"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Delete db"
        android:textAllCaps="false"/>

    <Button
        android:id="@+id/query_db"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Query db"
        android:textAllCaps="false"/>

</LinearLayout>

package com.leixiansheng.litepaltest;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import org.litepal.crud.DataSupport;
import org.litepal.tablemanager.Connector;

import java.util.List;

/**
 * LitePal：更快捷地操作数据库
 */
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private final static String TAG = "MainActivity";

    private Button btnCreateDB;
    private Button btnAddBookData;
    private Button btnUpdateBookData;
    private Button btnUpdateBookData2;
    private Button btnDeleteData;
    private Button btnQueryData;

    private Book book;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initView();
        setOnclick();
    }

    private void setOnclick() {
        btnCreateDB.setOnClickListener(this);
        btnAddBookData.setOnClickListener(this);
        btnUpdateBookData.setOnClickListener(this);
        btnUpdateBookData2.setOnClickListener(this);
        btnDeleteData.setOnClickListener(this);
        btnQueryData.setOnClickListener(this);
    }

    private void initView() {
        btnCreateDB = (Button) findViewById(R.id.create_db);
        btnAddBookData = (Button) findViewById(R.id.add_db);
        btnUpdateBookData = (Button) findViewById(R.id.update_db);
        btnUpdateBookData2 = (Button) findViewById(R.id.update2_db);
        btnDeleteData = (Button) findViewById(R.id.delete_db);
        btnQueryData = (Button) findViewById(R.id.query_db);

        book = new Book();
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.create_db:                    //创建数据库
                Connector.getDatabase();
//                SQLiteDatabase sqLiteDatabase = Connector.getDatabase();
                break;

            case R.id.add_db:                       //添加数据
                book = new Book();
                book.setName("The Da Vinci Code");
                book.setPages(454);
                book.setAuthor("Dan Brown");
                book.setPress("Unknow");
                book.setPrice(16.96);

                book.save();
                toast("add ok");
                break;

            case R.id.update_db:                    //更新数据方式一
                book.setName("New Name");
                book.setAuthor("New Author");

                book.save();
                toast("update ok");
                break;

            case R.id.update2_db:                    //更新数据方式二（推荐）
                book = new Book();
                book.setPrice(14.95);
                book.setPress("Anchor");

                //更新条件筛选
                //book.updateAll();       //将所有数据还原为初始值
                book.updateAll("id = ? and author = ?", "1", "Dan Brown");     //id为1 且作者为author  会被更改
                toast("update2 ok");
                break;

            case R.id.delete_db:                      //删除数据
                //LitePal.deleteDatabase(Book.class);    //删除所有数据
                LitePal.deleteAll(Book.class, "price > ?", "15");
                toast("delete ok");
                break;

            case R.id.query_db:                         //查询所有
                List<Book> bookList = LitePal.findAll(Book.class);
                for (Book book:bookList) {
                    Log.i(TAG, "book name:" + book.getName());
                    Log.i(TAG, "book author:" + book.getAuthor());
                    Log.i(TAG, "book pages:" + book.getPages());
                    Log.i(TAG, "book price:" + book.getPrice());
                    Log.i(TAG, "book press:" + book.getPress());
                }

                /* 其他查询方式
                List<Book> bookList = DataSupport.findFirst(Book.class);    //查询第一条
                List<Book> bookList = DataSupport.findLast(Book.class);    //查询最后一条
                List<Book> bookList = DataSupport.where("pages > ?", "400");    //条件查询
                List<Book> bookList = DataSupport.order("price desc");    //查询后排序  desc降序  asc升序
                ........
                */
        }
    }

    private void toast(String str) {
        Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
    }
}

原文链接：https://blog.csdn.net/Mr_Leixiansheng/article/details/77163225

转载请注明出处： 更快捷操作数据库 LitePal_Mr_Leixiansheng的博客-CSDN博客

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