17 Android 数据库

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package com.db.test;import java.sql.SQLDataException;import android.R.string;import android.app.Activity;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.os.Bundle;import android.util.Log;public class DBTestActivity extends Activity {    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                MyDataBaseOpenHelper mydb=new MyDataBaseOpenHelper(this);        mydb.getReadableDatabase();        //        mydb.insertDB("Tom", "BJING");//        mydb.insertDB("Jack", "NANJING");//        mydb.insertDB("Ting", "TIDDA");        mydb.deleteDB("Tom");        Cursor cs=mydb.queryDB();        cs.moveToFirst();        while(!cs.isLast())        {        String str1=cs.getString(cs.getColumnIndex("name"));        String str2=cs.getString(cs.getColumnIndex("address"));        Log.d(">>>>姓名<<<<", str1);        Log.d(">>>>地址<<<<", str2);        cs.moveToNext();        }        }class MyDataBaseOpenHelper extends SQLiteOpenHelper{Context context;private static final String DB_NAME="mydb.db";//数据库的名字private static final int VERSION=1;//数据库的版本public MyDataBaseOpenHelper(Context context) {super(context, DB_NAME, null, VERSION);// TODO Auto-generated constructor stub}@Overridepublic void onCreate(SQLiteDatabase db) {// TODO Auto-generated method stub//建表语句执行String sqlStr="create table person(_id integer primary key "+ "autoincrement,name text,address text)";//执行sql语句db.execSQL(sqlStr);}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {// TODO Auto-generated method stubString sql="alter table person add age integer";db.execSQL(sql);}/** * 插入数据 * @param name * @param address * @return */public long insertDB(String name,String address){SQLiteDatabase db=this.getWritableDatabase();ContentValues cv=new ContentValues();cv.put("name", name);cv.put("address", address);return db.insert("person", null, cv);}/** * 删除数据 * @param id * @return */public long deleteDB(String name){SQLiteDatabase db=this.getWritableDatabase();String where="name=?";String [] whereValue={name};return db.delete("person", where, whereValue);}/** * 更新数据 * @param id * @param name * @param address * @return */public long updateDB(String id ,String name,String address){SQLiteDatabase db=this.getWritableDatabase();ContentValues cv=new ContentValues();cv.put("name", name);cv.put("address", address);String where="_id=?";String[] whereValue={id};return db.update("person", cv, where, whereValue);}    public Cursor queryDB(){SQLiteDatabase db=this.getReadableDatabase();Cursor cursor=db.query("person", null, null, null, null, null, null);return cursor;}}}
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