安卓操作sqlite3，增删改查
创建 layout <?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" /> </LinearLayout> main package demo.jq.com.databasetest; import android.content.Context; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; /** * @author jim */ public class MainActivity extends AppCompatActivity { /** * 引入数据库助手类 */ private MyDatabaseHelper dbHelper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); dbHelper = new MyDatabaseHelper(this,"BookStore.db",null,2); // 初始化创建按钮 Button createDatabase = (Button) findViewById(R.id.create_database); // 设置点击事件 createDatabase.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v) { // 执行写入数据库操作 dbHelper.getWritableDatabase(); } }); } } helper package demo.jq.com.databasetest; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.widget.Toast; /** * @author Jim */ public class MyDatabaseHelper extends SQLiteOpenHelper { public static final String CREATE_BOOK = "create table Book(" + "id integer primary key autoincrement," + "author text," + "price real," // 浮点型 + "pages integer," + "name text)"; // 文本类型 public static final String CREATE_CATEGORY = "create table Category (" + "id integer primary key autoincrement," + "category_name text," + "category_code integer)"; private Context mContext; public MyDatabaseHelper(Context context, String name, SQLiteDatabase.CursorFactory factory,int version) { super(context,name,factory,version); mContext = context; } /** * 数据库创建的时候，才执行 * 如果数据库已经存在，将不会执行这个方法 * @param db */ @Override public void onCreate(SQLiteDatabase db) { // 执行sql语句 db.execSQL(CREATE_BOOK); db.execSQL(CREATE_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); } } 添加数据 <Button android:id="@+id/add_data" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Add data" /> // 初始化添加数据按钮 Button addData = (Button) findViewById(R.id.add_data); addData.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v) { 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); // 插入第一条数据 db.insert("Book",null,values); // 开始组装第二条数据 values.put("name","The Lost Symbol"); values.put("author","Dan Brown"); values.put("pages",510); values.put("price",19.95); // 插入第二条数据 db.insert("Book",null,values); } }); 修改数据 <Button android:id="@+id/update_data" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Update data" /> // 更改数据 Button updateData = (Button) findViewById(R.id.update_data); updateData.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v) { SQLiteDatabase db = dbHelper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("price",18.95); // 修改数据 db.update("Book",values,"id = ?",new String[] {"1"}); } }); 删除数据 <Button android:id="@+id/delete_data" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Delete data" /> // 删除数据 Button deleteData = (Button) findViewById(R.id.delete_data); deleteData.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v) { SQLiteDatabase db = dbHelper.getWritableDatabase(); // 删除数据 db.delete("Book","pages > ?",new String[] {"500"}); } }); 查询数据 <Button android:id="@+id/query_data" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Query data" /> // 查询数据 Button queryData = (Button) findViewById(R.id.query_data); queryData.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View v) { SQLiteDatabase db = dbHelper.getWritableDatabase(); // 查询Book表中所有的数据 Cursor cursor = db.query("Book",null,null,null,null,null,null); if (cursor.moveToFirst()) { do { // 遍历Cursor对象，取出数据 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(TAG,"book name is "+name); Log.d(TAG,"book author is "+author); Log.d(TAG,"book pages is "+pages); Log.d(TAG,"book price is "+price); } while (cursor.moveToNext()); } cursor.close(); } }); 本文转自TBHacker博客园博客，原文链接：http://www.cnblogs.com/jiqing9006/p/7698573.html，如需转载请自行联系原作者
