简单实现Android数据库的增删改查操作。

 MySQLiteHelper.java

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import androidx.annotation.Nullable;

public class MySQLiteHelper extends SQLiteOpenHelper {
    public static final String DB_NAME="bookstore.db";
    public static final int DB_VERSION=2;
    public MySQLiteHelper(@Nullable Context context)
    {super(context,DB_NAME,null,DB_VERSION);}

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        updateMyDatabase(sqLiteDatabase,0,DB_VERSION);
    }
    public static void insertBook(SQLiteDatabase sqLiteDatabase,String name,String isbn,String description,int imageId){
        ContentValues contentValues=new ContentValues();
        contentValues.put("NAME",name);
        contentValues.put("DESCRIPTION",description);
        contentValues.put("ISBN",isbn);
        contentValues.put("IMAGE_ID",imageId);
        sqLiteDatabase.insert("BOOK",null,contentValues);
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }
    public void updateMyDatabase(SQLiteDatabase sqLiteDatabase,int i,int i1){
        if (i<1){
            sqLiteDatabase.execSQL("CREATE TABLE BOOK(_id INTEGER PRIMARY KEY AUTOINCREMENT," +
                    "NAME TEXT,ISBN TEXT,DESCRIPTION TEXT,IMAGE_ID INTEGER)");
            insertBook(sqLiteDatabase,"Android移动应用基础教程","9787113252502","本书是第一本Android入门书籍，共15章", R.drawable.book1);
            insertBook(sqLiteDatabase,"Android第一行代码（第二版）","978711343434","本书案例非常实用，深入浅出",R.drawable.book2);
            insertBook(sqLiteDatabase,"Head First Android开发","9787113544356","开发Android应用的快速指南和参考书",R.drawable.book3);
        }
        if (i<2){

        }
    }
}

 BookCategoryActivity.java

package com.example.computerbookstore;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;

public class BookCategoryActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_book_category);
        ListView listBook = findViewById(R.id.list_item);
        SQLiteOpenHelper helper = new MySQLiteHelper(this);

        try {
            SQLiteDatabase db = helper.getWritableDatabase();
            Cursor cursor = db.query("BOOK", new String[]{"_id","NAME"},
                    null, null,null,null,null);
            SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
                    android.R.layout.simple_list_item_1, cursor, new String[]{"NAME"},
                    new int[]{android.R.id.text1}, 0);
            listBook.setAdapter(adapter);

        } catch (SQLiteException e) {
            Toast.makeText(this, "数据库不能被创建", Toast.LENGTH_LONG).show();
        }
        listBook.setOnItemClickListener(this);

    }


    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
        Intent intent = new Intent(this, BookActivity.class);
        intent.putExtra(BookActivity.EXTRA_BOOKID, (int) l);
        startActivity(intent);
    }

}

BookActivity.java

package com.example.computerbookstore;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import java.util.jar.Attributes;

public class BookActivity extends AppCompatActivity {
    public static final String EXTRA_BOOKID="bookId";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_book);
        EditText etName=findViewById(R.id.et_name);
        EditText etIsbn=findViewById(R.id.et_isbn);
        EditText etdescription=findViewById(R.id.et_description);
        ImageView ivBook=findViewById(R.id.imageView);
        Button btx=findViewById(R.id.button);
        Button bts=findViewById(R.id.button2);
        SQLiteOpenHelper helper=new MySQLiteHelper(this);
        int bookId=getIntent().getIntExtra(EXTRA_BOOKID,0);
        try {
            SQLiteDatabase sqLiteDatabase=helper.getReadableDatabase();
            Cursor cursor=sqLiteDatabase.query("BOOK",new String[]{"NAME","ISBN","DESCRIPTION","IMAGE_ID"},"_id=?",new String[]{Integer.toString(bookId)},null,null,null);
            if (cursor.moveToFirst()){
                String name=cursor.getString(0);
                etName.setText(name);
                String isbn=cursor.getString(1);
                etIsbn.setText(isbn);
                String description=cursor.getString(2);
                etdescription.setText(description);
                int id=cursor.getInt(3);
                ivBook.setImageResource(id);
            }
            cursor.close();
            sqLiteDatabase.close();
        }catch (SQLException e){
            Toast.makeText(this, "数据库创建失败", Toast.LENGTH_SHORT).show();
        }
        try {
            bts.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    SQLiteDatabase sqLiteDatabase = helper.getWritableDatabase();
                    sqLiteDatabase.delete("BOOK", "_id=?", new String[]{Integer.toString(bookId)});
                }
            });
        }catch (SQLException e){
            Toast.makeText(this,"此书信息已被删除",Toast.LENGTH_SHORT).show();
        }
        try {
            btx.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    SQLiteDatabase sqLiteDatabase=helper.getWritableDatabase();
                    ContentValues isbnValues=new ContentValues();
                    ContentValues nameValues=new ContentValues();
                    ContentValues descriptionValues=new ContentValues();
                    isbnValues.put("ISBN",etIsbn.getText().toString());
                    sqLiteDatabase.update("BOOK",isbnValues,"_id=?",new String[]{Integer.toString(bookId)});
                    nameValues.put("NAME",etName.getText().toString());
                    sqLiteDatabase.update("BOOK",nameValues,"_id=?",new String[]{Integer.toString(bookId)});
                    descriptionValues.put("DESCRIPTION",etdescription.getText().toString());
                    sqLiteDatabase.update("BOOK",descriptionValues,"_id=?",new String[]{Integer.toString(bookId)});
                }
            });
        }catch (SQLException e){
            Toast.makeText(this,"修改成功",Toast.LENGTH_SHORT).show();
        }
    }
}

activity_book.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".BookActivity">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:srcCompat="@drawable/book1" />

    <TextView
        android:id="@+id/tv_name"
        android:layout_width="85dp"
        android:layout_height="60dp"
        android:gravity="center"
        android:layout_centerVertical="true"
        android:layout_below="@id/imageView"
        android:textSize="18sp"
        android:layout_marginTop="2dp"
        android:text="书籍名称: " />

    <EditText
        android:id="@+id/et_name"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_toRightOf="@id/tv_name"
        android:layout_below="@id/imageView"
        android:ems="100" />

    <TextView
        android:id="@+id/tv_isbn"
        android:layout_width="85dp"
        android:gravity="center"
        android:layout_height="60dp"
        android:textSize="18sp"
        android:layout_below="@id/tv_name"
        android:text="ISBN: " />

    <EditText
        android:id="@+id/et_isbn"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_below="@id/et_name"
        android:layout_toRightOf="@id/tv_isbn"
        android:ems="100" />

    <TextView
        android:id="@+id/tv_description"
        android:layout_width="85dp"
        android:layout_height="60dp"
        android:gravity="center"
        android:textSize="18sp"
        android:layout_below="@id/tv_isbn"
        android:text="书籍简介: " />

    <EditText
        android:id="@+id/et_description"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_below="@id/et_isbn"
        android:layout_toRightOf="@id/tv_description"
        android:ems="100" />

    <Button
        android:id="@+id/button"
        android:layout_marginLeft="20dp"
        android:layout_width="80dp"
        android:layout_height="50dp"
        android:padding="10dp"
        android:layout_below="@id/et_description"
        android:text="修改" />

    <Button
        android:id="@+id/button2"
        android:layout_width="80dp"
        android:layout_height="50dp"
        android:layout_marginRight="20dp"
        android:padding="10dp"
        android:layout_alignParentRight="true"
        android:layout_below="@id/et_description"
        android:text="删除" />

</RelativeLayout>

activity_book_category.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".BookActivity">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:srcCompat="@drawable/book1" />

    <TextView
        android:id="@+id/tv_name"
        android:layout_width="85dp"
        android:layout_height="60dp"
        android:gravity="center"
        android:layout_centerVertical="true"
        android:layout_below="@id/imageView"
        android:textSize="18sp"
        android:layout_marginTop="2dp"
        android:text="书籍名称: " />

    <EditText
        android:id="@+id/et_name"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_toRightOf="@id/tv_name"
        android:layout_below="@id/imageView"
        android:ems="100" />

    <TextView
        android:id="@+id/tv_isbn"
        android:layout_width="85dp"
        android:gravity="center"
        android:layout_height="60dp"
        android:textSize="18sp"
        android:layout_below="@id/tv_name"
        android:text="ISBN: " />

    <EditText
        android:id="@+id/et_isbn"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_below="@id/et_name"
        android:layout_toRightOf="@id/tv_isbn"
        android:ems="100" />

    <TextView
        android:id="@+id/tv_description"
        android:layout_width="85dp"
        android:layout_height="60dp"
        android:gravity="center"
        android:textSize="18sp"
        android:layout_below="@id/tv_isbn"
        android:text="书籍简介: " />

    <EditText
        android:id="@+id/et_description"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_below="@id/et_isbn"
        android:layout_toRightOf="@id/tv_description"
        android:ems="100" />

    <Button
        android:id="@+id/button"
        android:layout_marginLeft="20dp"
        android:layout_width="80dp"
        android:layout_height="50dp"
        android:padding="10dp"
        android:layout_below="@id/et_description"
        android:text="修改" />

    <Button
        android:id="@+id/button2"
        android:layout_width="80dp"
        android:layout_height="50dp"
        android:layout_marginRight="20dp"
        android:padding="10dp"
        android:layout_alignParentRight="true"
        android:layout_below="@id/et_description"
        android:text="删除" />

</RelativeLayout>