sqlite数据库存储
方法一、命令行模式。在环境变量Path中配置Platform-tools的路径,输入 adb shell,输入 cd /data/data/cn.bzu.tong.sqlite/databases,输入 sqlite3 BookStore.db,输入 .table查看数据库中的表,输入.scheme,查看建表语句,输入 select * from Book查看表中内容(自己运行显示不出内容)。
方法二、Navicat模式。模拟器运行,点击Create database等按钮,每一次都将模拟器中的BookStore.db导出,在Navicat中新建连接后导入该数据库,打开book表查看表中信息。
一、运行效果
1、Create databases
2、Add data 添加数据
3、Update data 更新数据
4、Delete Data 删除数据
5、Quary data 查询数据
Logcat显示如下图:
7、模拟器界面MainActivity.xml
二、核心代码
MainActivity.java
package cn.bzu.tong.sqlite; import android.app.Activity; import android.content.ContentValues; import android.database.Cursor; import android.database.sqlite.sqliteDatabase; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import cn.bzu.tong.sqlist.R; import cn.bzu.tong.sqlite.db.DBHelper; public class MainActivity extends Activity { private DBHelper dbHelper; private Button createDatabase,addData,updateData,deleteData,queryData; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); dbHelper = new DBHelper(this,"BookStore.db",null,2); queryData = (Button) findViewById(R.id.query_data); deleteData = (Button) findViewById(R.id.delete_data); updateData = (Button) findViewById(R.id.update_data); addData = (Button) findViewById(R.id.add_data); createDatabase = (Button) findViewById(R.id.creat_database); createDatabase.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { dbHelper.getWritableDatabase(); } }); addData.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { sqliteDatabase db = dbHelper.getWritableDatabase(); ContentValues values = new ContentValues(); //开始组装第一条数据 values.put("name","The Da Vinci Code"); values.put("author","Dan Brown"); values.put("pages",454); values.put("price",16.96); db.insert("Book",values);//插入第一条数据 values.clear(); //开始组装第二条数据 } }); updateData.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { sqliteDatabase db = dbHelper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("price",10.99); db.update("Book",values,"name=?",new String[]{"The Da Vinci Code"}); } }); deleteData.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { sqliteDatabase db = dbHelper.getWritableDatabase(); db.delete("Book","pages > ?",new String[]{"400"});//范围 } queryData.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { sqliteDatabase db = dbHelper.getWritableDatabase(); //查询Book表中所有数据 Cursor cursor = db.query("Book",null); if(cursor.moveToFirst()){ do{ //遍历Cursor对象,取出数据并打印 String name = cursor.getString(cursor.getColumnIndex("name")); String author = cursor.getString(cursor.getColumnIndex("author")); int pages = cursor.getInt(cursor.getColumnIndex("pages")); double price = cursor.getDouble(cursor.getColumnIndex("price")); Log.d("MainActivity","book name is "+name); }while(cursor.moveToNext()); } cursor.close(); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main,menu); return true; } }
DBHelper.java
package cn.bzu.tong.sqlite.db; import android.content.Context; import android.database.sqlite.sqliteDatabase; import android.database.sqlite.sqliteDatabase.CursorFactory; import android.database.sqlite.sqliteOpenHelper; import android.widget.Toast; public class DBHelper extends sqliteOpenHelper { public static final String CREATE_TABLE_BOOK = "create table book(" + "id integer primary key autoincrement," + "author text," + "price real," + "pages integer," + "name text)"; private Context mContext; public static final String CREATE_TABLE_CATEGORY="create table Category(id integer primary key autoincrement," + "category_name text,category_code integer)"; public DBHelper(Context context,String name,CursorFactory factory,int version) { super(context,name,factory,version); mContext = context; } @Override public void onCreate(sqliteDatabase db) { db.execsql(CREATE_TABLE_BOOK); db.execsql(CREATE_TABLE_CATEGORY); Toast.makeText(mContext,"create succeeded",Toast.LENGTH_SHORT).show(); } @Override public void onUpgrade(sqliteDatabase db,int oldVersion,int newVersion) { db.execsql("drop table if exists Book"); db.execsql("drop table if exists Category"); onCreate(db); } }
activity_main.xml
<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=".MainActivity" android:orientation="vertical" > <Button android:id="@+id/creat_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>原文链接:https://www.f2er.com/sqlite/198653.html