ContentValues的使用

package com.example.ContentValuesDemo;

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

public class DemoHelper extends SQLiteOpenHelper {
      public DemoHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
            super(context, name, factory, version);
      }

      @Override
      public void onCreate(SQLiteDatabase db) {
            db.execSQL("create table stu (id integer primary key autoincrement,name text not null,age text not null)");

      }

      @Override
      public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

            db.execSQL("drop table if exists stu");
            onCreate(db);

      }
}

使用contentValues写方法：直接用db的insert，delete，update方法。id用占位符...

package com.example.ContentValuesDemo;

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

/**
 * Created by Anonymous on 2016/1/19.
 */
public class DemoMethods {

      private SQLiteDatabase db;
      private static final  String DataName = "stu";

      public DemoMethods(SQLiteDatabase db) {
            this.db = db;
      }

      public void insertData(String name,String age){

            ContentValues cv = new ContentValues();
            cv.put("name", name);
            cv.put("age",age);
            db.insert(DataName, null, cv);

      }

      public void deleteData(int id ){
            String whereCause = "id=?";
            String[] whereArgs = new String[]{String.valueOf(id)};
            ContentValues cv = new ContentValues();
            db.delete(DataName, whereCause, whereArgs);
      }

      public void updataData(int id,String name,String age){

            String whereCause = "id=?";
            String[] whereArgs = new String[]{String.valueOf(id)};

            ContentValues cv = new ContentValues();
            cv.put("name", name);
            cv.put("age", age);
            db.update(DataName, cv, whereCause, whereArgs);

      }
}

mainActivity引用：

package com.example.ContentValuesDemo;

import android.app.Activity;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;

public class MyActivity extends Activity {


      @Override
      public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            DemoHelper helper = new DemoHelper(MyActivity.this, "stu.db", null, 1);

            SQLiteDatabase db = helper.getWritableDatabase();

            DemoMethods methods = new DemoMethods(db);

            for (int i = 0; i < 5; i++) {

                  methods.insertData("mary" + i, "55");
            }

            for (int i = 1; i < 3; i++) {
                  
            methods.deleteData(i);
            }
            methods.updataData(3, "change", "100");
            db.close();
      }
}