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mars老师[Android开发视频教学].01_16_SQLite使用方法 视频源码

2012-05-20 18:25 811 查看
mars老师[Android开发视频教学].01_16_SQLite使用方法

主要内容:

1.SQLite的介绍

2.SQLiteOpenHelper的用法

3.使用adb访问SQLite

4.增、删、改、查

创建项目:sqlite

截图:



=>>SQLiteActivity.java

package mars.sqlite3;

import mars.sqlite3.db.DatabaseHelper;
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.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class SQLiteActivity extends Activity {
/** Called when the activity is first created. */
private Button createButton;
private Button insertButton;
private Button updateButton;
private Button updateRecordButton;
private Button queryButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
createButton = (Button)findViewById(R.id.createDatabase);
updateButton = (Button)findViewById(R.id.updateDatabase);
insertButton = (Button)findViewById(R.id.insert);
updateRecordButton = (Button)findViewById(R.id.update);
queryButton = (Button)findViewById(R.id.query);
createButton.setOnClickListener(new CreateListener());
updateButton.setOnClickListener(new UpdateListener());
insertButton.setOnClickListener(new InsertListener());
updateRecordButton.setOnClickListener(new UpdateRecordListener());
queryButton.setOnClickListener(new QueryListener());
}
class CreateListener implements OnClickListener{
@Override
public void onClick(View v) {
//创建一个DatabaseHelper对象
DatabaseHelper dbHelper = new DatabaseHelper(SQLiteActivity.this,"test_mars_db");
//只有调用了DatabaseHelper对象的getReadableDatabase()方法,或者是getWritableDatabase()方法之后,才会创建,或打开一个数据库
SQLiteDatabase db = dbHelper.getReadableDatabase();
}
}
class UpdateListener implements OnClickListener{

@Override
public void onClick(View v) {
DatabaseHelper dbHelper = new DatabaseHelper(SQLiteActivity.this,"test_mars_db",2);
SQLiteDatabase db = dbHelper.getReadableDatabase();
}

}
class InsertListener implements OnClickListener{

@Override
public void onClick(View v) {
//生成ContentValues对象
ContentValues values = new ContentValues();
//想该对象当中插入键值对,其中键是列名,值是希望插入到这一列的值,值必须和数据库当中的数据类型一致
values.put("id", 1);
values.put("name","zhangsan");
DatabaseHelper dbHelper = new DatabaseHelper(SQLiteActivity.this,"test_mars_db",2);
SQLiteDatabase db = dbHelper.getWritableDatabase();
//调用insert方法,就可以将数据插入到数据库当中
db.insert("user", null, values);
}
}
//更新操作就相当于执行SQL语句当中的update语句
//UPDATE table_name SET XXCOL=XXX WHERE XXCOL=XX...
class UpdateRecordListener implements OnClickListener{

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
//得到一个可写的SQLiteDatabase对象
DatabaseHelper dbHelper = new DatabaseHelper(SQLiteActivity.this,"test_mars_db");
SQLiteDatabase db = dbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name", "zhangsanfeng");
//第一个参数是要更新的表名
//第二个参数是一个ContentValeus对象
//第三个参数是where子句
db.update("user", values, "id=?", new String[]{"1"});
}
}
class QueryListener implements OnClickListener{

@Override
public void onClick(View v) {
System.out.println("aaa------------------");
Log.d("myDebug", "myFirstDebugMsg");

DatabaseHelper dbHelper = new DatabaseHelper(SQLiteActivity.this,"test_mars_db");
SQLiteDatabase db = dbHelper.getReadableDatabase();
Cursor cursor = db.query("user", new String[]{"id","name"}, "id=?", new String[]{"1"}, null, null, null);
while(cursor.moveToNext()){
String name = cursor.getString(cursor.getColumnIndex("name"));
System.out.println("query--->" + name);
}
}
}

}


=>>DatabaseHelper.java

package mars.sqlite3.db;

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

//DatabaseHelper作为一个访问SQLite的助手类,提供两个方面的功能,
//第一,getReadableDatabase(),getWritableDatabase()可以获得SQLiteDatabse对象,通过该对象可以对数据库进行操作
//第二,提供了onCreate()和onUpgrade()两个回调函数,允许我们在创建和升级数据库时,进行自己的操作

public class DatabaseHelper extends SQLiteOpenHelper {

private static final int VERSION = 1;
//在SQLiteOepnHelper的子类当中,必须有该构造函数
public DatabaseHelper(Context context, String name, CursorFactory factory,
int version) {
//必须通过super调用父类当中的构造函数
super(context, name, factory, version);
// TODO Auto-generated constructor stub
}
public DatabaseHelper(Context context,String name){
this(context,name,VERSION);
}
public DatabaseHelper(Context context,String name,int version){
this(context, name,null,version);
}

//该函数是在第一次创建数据库的时候执行,实际上是在第一次得到SQLiteDatabse对象的时候,才会调用这个方法
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
System.out.println("create a Database");
//execSQL函数用于执行SQL语句
db.execSQL("create table user(id int,name varchar(20))");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
System.out.println("update a Database");
}

}
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