第一行代码 6.4 数据存储全方案-详解持久化数据- 数据库

 

 

 

 

 

 

 

参看前面：

 

之前创建的数据

Book表中，通过values传入一组数据

数据中有 price要修改

来修改原来的数据

 

 

 

 

 

 

               

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.2"

    defaultConfig {
        applicationId "com.example.litepaltest"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.2.1'
    compile 'org.litepal.android:core:1.3.2'
}

　　

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

    <version value="2" ></version>

    <list>
       
    </list>
</litepal>

　　

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.litepaltest">

    <application
        android: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>

</manifest>

　　

          

 

package com.example.litepaltest;

import org.litepal.crud.DataSupport;

public class Book extends DataSupport {

    private int id;

    private String author;

    private double price;

    private int pages;

    private String name;

    private String press;

    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;
    }

    public String getPress() {
        return press;
    }

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

}

　　 

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

    <version value="2" ></version>

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

　　

 

package com.example.litepaltest;

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

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

import java.util.List;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button createDatabase = (Button) findViewById(R.id.create_database);
        createDatabase.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Connector.getDatabase();
            }
        });
    }
}

　　

 

 

package com.example.litepaltest;

import org.litepal.crud.DataSupport;

public class Book extends DataSupport {

    private int id;

    private String author;

    private double price;

    private int pages;

    private String name;

    private String press;

    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;
    }

    public String getPress() {
        return press;
    }

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

}

　　

package com.example.litepaltest;

public class Category {

    private int id;

    private String categoryName;

    private int categoryCode;

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

    public void setCategoryName(String categoryName) {
        this.categoryName = categoryName;
    }

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

}

 

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

    <version value="2" ></version>

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

　　

 

 

 Button addData = (Button) findViewById(R.id.add_data);
        addData.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Book book = new Book();
                book.setName("The Da Vinci Code");
                book.setAuthor("Dan Brown");
                book.setPages(454);
                book.setPrice(16.96);
                book.setPress("Unknow");
                book.save();
            }
        });

　　

 

　　

 

 Button updateData = (Button) findViewById(R.id.update_data);
        updateData.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Book book = new Book();
                book.setPrice(14.95);
                book.setPress("Anchor");
                book.updateAll("name = ? and author = ?", "The Lost Symbol", "Dan Brown");
            }
        });

　　

 

   Button deleteButton = (Button) findViewById(R.id.delete_data);
        deleteButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DataSupport.deleteAll(Book.class, "price < ?", "15");
            }
        });

　　

  Button queryButton = (Button) findViewById(R.id.query_data);
        queryButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                List<Book> books = DataSupport.findAll(Book.class);
                for (Book book: books) {
                    Log.d("MainActivity", "book name is " + book.getName());
                    Log.d("MainActivity", "book author is " + book.getAuthor());
                    Log.d("MainActivity", "book pages is " + book.getPages());
                    Log.d("MainActivity", "book price is " + book.getPrice());
                    Log.d("MainActivity", "book press is " + book.getPress());
                }
            }
        });

　　

文件工程：

1AndroidManifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.litepaltest">

    <application
        android: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>

</manifest>

　

2数据库

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

    <version value="2" ></version>

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

　　

3 类

 

MainActivity

package com.example.litepaltest;

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

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

import java.util.List;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button createDatabase = (Button) findViewById(R.id.create_database);
        createDatabase.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Connector.getDatabase();
            }
        });

        Button addData = (Button) findViewById(R.id.add_data);
        addData.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Book book = new Book();
                book.setName("The Da Vinci Code");
                book.setAuthor("Dan Brown");
                book.setPages(454);
                book.setPrice(16.96);
                book.setPress("Unknow");
                book.save();
            }
        });
        Button updateData = (Button) findViewById(R.id.update_data);
        updateData.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Book book = new Book();
                book.setPrice(14.95);
                book.setPress("Anchor");
                book.updateAll("name = ? and author = ?", "The Lost Symbol", "Dan Brown");
            }
        });
        Button deleteButton = (Button) findViewById(R.id.delete_data);
        deleteButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DataSupport.deleteAll(Book.class, "price < ?", "15");
            }
        });
        Button queryButton = (Button) findViewById(R.id.query_data);
        queryButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                List<Book> books = DataSupport.findAll(Book.class);
                for (Book book: books) {
                    Log.d("MainActivity", "book name is " + book.getName());
                    Log.d("MainActivity", "book author is " + book.getAuthor());
                    Log.d("MainActivity", "book pages is " + book.getPages());
                    Log.d("MainActivity", "book price is " + book.getPrice());
                    Log.d("MainActivity", "book press is " + book.getPress());
                }
            }
        });
    }

}

Book

package com.example.litepaltest;

import org.litepal.crud.DataSupport;

public class Book extends DataSupport {

    private int id;

    private String author;

    private double price;

    private int pages;

    private String name;

    private String press;

    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;
    }

    public String getPress() {
        return press;
    }

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

}

Category

package com.example.litepaltest;

public class Category {

    private int id;

    private String categoryName;

    private int categoryCode;

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

    public void setCategoryName(String categoryName) {
        this.categoryName = categoryName;
    }

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

}

　　4 主布局

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

    <Button
        android:id="@+id/create_database"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Create database"
        />

    <Button
        android:id="@+id/add_data"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Add data"
        />

    <Button
        android:id="@+id/update_data"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Update data"
        />

    <Button
        android:id="@+id/delete_data"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Delete data"
        />

    <Button
        android:id="@+id/query_data"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Query data"
        />

</LinearLayout>