Android学习笔记10：SQLite的简单学习
[Android开发视频教学].01_16_SQLite使用方法
学习使用SQLiteOpenHelper，SQLDataBase，ContentValues
感觉SQLiteOpenHelper不好用，有许多操作感觉很繁琐，不过还是看懂了，并且做了实现
注：生成数据库操作只能生成一次，没有找到删除数据库的方法，这里写的代码如果执行是会报错的，所以没有将此事件绑定到监听器上
布局
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="false"
android:layout_centerVertical="false"
android:text="@string/hello_world"
tools:context=".Activity13" />
<Button
android:id="@+id/createDB"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/textView1"
android:text="@string/createDB" />
<Button
android:id="@+id/upgradeDB"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/createDB"
android:text="@string/upgradeDB" />
<Button
android:id="@+id/deleteDB"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/upgradeDB"
android:text="@string/deleteDB" />
<Button
android:id="@+id/insert"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/deleteDB"
android:text="@string/insert" />
<Button
android:id="@+id/update"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/insert"
android:text="@string/update" />
<Button
android:id="@+id/query"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/update"
android:text="@string/query" />
<Button
android:id="@+id/delete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/query"
android:text="@string/delete" />
</RelativeLayout>
国际化
<resources>
<string name="app_name">SQLite操作</string>
<string name="hello_world">Hello world!</string>
<string name="menu_settings">Settings</string>
<string name="title_activity_activity13">SQLite操作</string>
<string name="createDB">创建数据库</string>
<string name="upgradeDB">升级数据库</string>
<string name="deleteDB">删除数据库</string>
<string name="insert">添加数据</string>
<string name="update">更新数据</string>
<string name="query">查询数据</string>
<string name="delete">删除数据</string>
</resources>
Main
package fengda.android13;
import java.io.File;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class Activity13 extends Activity {
private Button createDB;
private Button upgradeDB;
private Button deleteDB;
private Button insert;
private Button update;
private Button query;
private Button delete;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activity13);
createDB = (Button) findViewById(R.id.createDB);
createDB.setOnClickListener(new CreateDBClickListenen());
upgradeDB = (Button) findViewById(R.id.upgradeDB);
upgradeDB.setOnClickListener(new UpgradeDBClickListener());
deleteDB = (Button) findViewById(R.id.deleteDB);
//deleteDB.setOnClickListener( new DeleteDBClickListener());
insert = (Button) findViewById(R.id.insert);
insert.setOnClickListener(new InsertClickListener());
update = (Button) findViewById(R.id.update);
update.setOnClickListener(new UpdateClickListener());
query = (Button) findViewById(R.id.query);
query.setOnClickListener(new QueryClickListener());
delete = (Button) findViewById(R.id.delete);
delete.setOnClickListener(new DeleteClickListener());
}
//创建数据库
class CreateDBClickListenen implements OnClickListener{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyDBHelper myDBHelper = new MyDBHelper(Activity13.this,"android13");
myDBHelper.getReadableDatabase();
}
}
//更新数据库版本
class UpgradeDBClickListener implements OnClickListener{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyDBHelper myDBHelper = new MyDBHelper(Activity13.this,"android13",2);
myDBHelper.getReadableDatabase();
}
}
//删除数据库
class DeleteDBClickListener implements OnClickListener {
@SuppressLint("NewApi")
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyDBHelper myDBHelper = new MyDBHelper(Activity13.this,"android13");
SQLiteDatabase db = myDBHelper.getWritableDatabase();
db.deleteDatabase(new File("android13"));
}
}
//添加一条数据信息
class InsertClickListener implements OnClickListener {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyDBHelper myDBHelper = new MyDBHelper(Activity13.this,"android13");
SQLiteDatabase db = myDBHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("id", 1);
values.put("name", "牛牛");
db.insert("person", null, values);
}
}
//更新数据
class UpdateClickListener implements OnClickListener {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyDBHelper myDBHelper = new MyDBHelper(Activity13.this,"android13");
SQLiteDatabase db = myDBHelper.getReadableDatabase();
ContentValues values = new ContentValues();
values.put("name", "niuniu");
db.update("person", values, "id=?", new String[]{"1"});
}
}
//查询数据
class QueryClickListener implements OnClickListener {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyDBHelper myDBHelper = new MyDBHelper(Activity13.this,"android13");
SQLiteDatabase db = myDBHelper.getReadableDatabase();
Cursor cursor = db.query("person", new String[]{"id","name"}, "id=?", new String[]{"1"} , null, null, null);
while(cursor!=null && cursor.moveToNext()){
int id = cursor.getInt(cursor.getColumnIndex("id"));
String name = cursor.getString(cursor.getColumnIndex("name"));
System.out.println("id="+id+", name="+name);
}
}
}
//删除数据
class DeleteClickListener implements OnClickListener {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyDBHelper myDBHelper = new MyDBHelper(Activity13.this,"android13");
SQLiteDatabase db = myDBHelper.getWritableDatabase();
db.delete("person", "id=?", new String[]{"1"});
}
}
}
package fengda.android13;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class MyDBHelper extends SQLiteOpenHelper {
public static final int VERSION=1;
public MyDBHelper(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
// TODO Auto-generated constructor stub
}
public MyDBHelper(Context context,String name,int version){
this(context,name,null,version);
}
public MyDBHelper(Context context,String name){
this(context,name,VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
System.out.println("创建一个数据库");
db.execSQL("create table person(id int, name varchar(20))");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
System.out.println("升级数据库");
}
}
截图：
Android调试起来不方便，下一讲正好讲调试操作，哈哈。