Android sqlite本機資料庫

做任何開發都會用的資料庫，Android也一樣，Android一般都要用的兩個資料庫本機資料庫和遠端資料庫，本機資料庫就是sqlite，遠端資料庫的話，我一般用的是mysql，這次先瞭解下本機資料庫sqlite，一般資料庫類型為varchar(20) 如果你輸入個大於20位的資料時，會報錯，不能插入吧，但是sqlite裡就不一樣了，他就可以，這是sqlite的特色之一吧應該是。下來就看看sqlite的 crud：

MainActivity

package com.example.sqlite;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.widget.TextView;public class MainActivity extends Activity {    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        TextView t;                DBOpenHelter dbopenhelper=new DBOpenHelter(this);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.activity_main, menu);        return true;    }}

PersonService

package com.example.sqlite;import com.example.bean.Person;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;public class PersonService {private DBOpenHelter dbOpenHelper;public PersonService(Context context){this.dbOpenHelper=new DBOpenHelter(context);}public void save(Person person){SQLiteDatabase db=dbOpenHelper.getWritableDatabase();StringBuilder sql=new StringBuilder(128);//這個沒用sql.append("insert ");//這個沒用db.execSQL("insert into person(name,phone) values(?,?)",new Object[]{person.getName(),person.getPhone()});db.close();}public Person find(Integer id){Person person=new Person();SQLiteDatabase db=dbOpenHelper.getReadableDatabase();Cursor cursor=db.rawQuery("select * from testpersion wehre name=?",new String[]{id.toString()});while(cursor.moveToNext()){int personid=cursor.getInt(cursor.getColumnIndex("id"));}return person;}}

DBOpenHelter

package com.example.sqlite;

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

public class DBOpenHelter extends SQLiteOpenHelper{

public DBOpenHelter(Context context) {
super(context, "itcast.db", null, 1);
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE testpersion(persionid integer primary key autoincrement,name varchar(20))");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("ALTER TABLE testpersion ADD phone VARCHAR(12) NULL");
}

}