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 {@Overridepublic 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();}}