SQLite数据库的创增改删查

<?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"
    android:orientation="vertical"
    tools:context="com.example.mjon.myapplication.MainActivity">

    <Button
        android:id="@+id/create"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:text="create" />

    <Button
        android:id="@+id/select"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:text="select" />

    <Button
        android:id="@+id/insert"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:text="insert" />

    <Button
        android:id="@+id/update"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:text="update" />

    <Button
        android:id="@+id/delete"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:text="delete" />

    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:padding="15dp"
        android:textColor="@android:color/black"
        android:textSize="18sp" />

</LinearLayout>

package com.example.mjon.myapplication;

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

public class MySQLiteHelper extends SQLiteOpenHelper {

    private Context mContext;

    private static final String CREATE_TABLE_BOOK = "create table Book(" +
            "id  integer primary key autoincrement," +
            "name text," +
            "price real," +
            "author text)";

    public MySQLiteHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
        mContext = context;
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        sqLiteDatabase.execSQL(CREATE_TABLE_BOOK);
    }

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

    }
}

package com.example.mjon.myapplication;

import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private MySQLiteHelper mySQLiteHelper;

    private SQLiteDatabase sqLiteDatabase;

    private Button create;
    private Button select;
    private Button insert;
    private Button update;
    private Button delete;
    private TextView tv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        create = (Button) findViewById(R.id.create);
        create.setOnClickListener(listener);
        select = (Button) findViewById(R.id.select);
        select.setOnClickListener(listener);
        insert = (Button) findViewById(R.id.insert);
        insert.setOnClickListener(listener);
        update = (Button) findViewById(R.id.update);
        update.setOnClickListener(listener);
        delete = (Button) findViewById(R.id.delete);
        delete.setOnClickListener(listener);
        mySQLiteHelper = new MySQLiteHelper(this, "BookStore.db", null, 1);
    }

    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            switch (view.getId()) {
                case R.id.create:
                    mySQLiteHelper.getWritableDatabase();
                    break;
                case R.id.select:
                    sqLiteDatabase = mySQLiteHelper.getReadableDatabase();
                    Cursor cursor = sqLiteDatabase.query("Book", null, null, null, null, null, null);
                    StringBuilder stringBuilder = new StringBuilder();
                    if (cursor.moveToFirst()) {
                        do {
                            String id = cursor.getString(cursor.getColumnIndex("id"));
                            String name = cursor.getString(cursor.getColumnIndex("name"));
                            String price = cursor.getString(cursor.getColumnIndex("price"));
                            String author = cursor.getString(cursor.getColumnIndex("author"));
                            stringBuilder.append(id + ";" + name + ";" + price + ";" + author);
                        } while (cursor.moveToNext());
                    }
                    tv.setText(stringBuilder.toString());
                    break;
                case R.id.insert:
                    sqLiteDatabase = mySQLiteHelper.getWritableDatabase();
                    ContentValues contentValues = new ContentValues();
                    contentValues.put("name", "数据分析");
                    contentValues.put("price", 37.20);
                    contentValues.put("author", "哥白尼");
                    sqLiteDatabase.insert("Book", null, contentValues);
                    contentValues.clear();
                    contentValues.put("name", "程序设计");
                    contentValues.put("price", 52.60);
                    contentValues.put("author", "爱因斯坦");
                    sqLiteDatabase.insert("Book", null, contentValues);
                    contentValues.clear();
                    contentValues.put("name", "网络技术");
                    contentValues.put("price", 86.20);
                    contentValues.put("author", "牛顿");
                    sqLiteDatabase.insert("Book", null, contentValues);
                    break;
                case R.id.update:
                    sqLiteDatabase = mySQLiteHelper.getWritableDatabase();
                    ContentValues cv = new ContentValues();
                    cv.put("price", 62);
                    sqLiteDatabase.update("Book", cv, "author = ?", new String[]{"牛顿"});
                    break;
                case R.id.delete:
                    sqLiteDatabase = mySQLiteHelper.getWritableDatabase();
                    sqLiteDatabase.delete("Book", "name = ?", new String[]{"数据分析"});
                    break;
                default:
                    break;
            }
        }
    };
}