006_02SQLite_OpenHelper

 1 package com.example.sqliteopenhelper;
 2
 3 import android.content.Context;
 4 import android.database.sqlite.SQLiteDatabase;
 5 import android.database.sqlite.SQLiteDatabase.CursorFactory;
 6 import android.database.sqlite.SQLiteOpenHelper;
 7 import android.util.Log;
 8
 9 public class MydbOpenHelper extends SQLiteOpenHelper{
10
11     public MydbOpenHelper(Context context, String name, CursorFactory factory, int version){
12         super(context, name, factory, version);
13     }
14
15     @Override
16     public void onCreate(SQLiteDatabase db) {
17         String createtable = "create table user(id int, name varchar(20), password char(8))";
18         db.execSQL(createtable);
19         System.out.println("MydbOpenHelper.onCreate()");
20
21     }
22
23     @Override
24     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
25         Log.i("MydbOpenHelper","oldVersion" + oldVersion + "newVersion" + newVersion);
26         System.out.println("MydbOpenHelper.onUpgrade()");
27
28     }
29 }

MydbOpenHelper

 1 package com.example.sqliteopenhelper;
 2
 3 import android.app.Activity;
 4 import android.content.ContentValues;
 5 import android.database.Cursor;
 6 import android.database.sqlite.SQLiteDatabase;
 7 import android.os.Bundle;
 8 import android.util.Log;
 9 import android.view.Menu;
10 import android.view.MenuItem;
11 import android.view.View;
12
13 public class MainActivity extends Activity {
14     SQLiteDatabase db = null;
15
16     @Override
17     protected void onCreate(Bundle savedInstanceState) {
18         super.onCreate(savedInstanceState);
19         setContentView(R.layout.activity_main);
20
21         MydbOpenHelper dbhelper = new MydbOpenHelper(this, "userinfo.db", null, 1);
22         db = dbhelper.getWritableDatabase();
23
24     }
25
26     public void insert(View v){
27         ContentValues c = new ContentValues();
28         //c.put("id", 2);
29         //c.put("name", "user222");
30         //c.put("password", "222");
31
32         c.put("id", 1);
33         c.put("name", "user1");
34         c.put("password", "222");
35
36         db.insert("user", null, c);
37     }
38     public void delete(View v){
39         db.delete("user", "id=? and name=?", new String[]{"1","user1"});
40     }
41     public void update(View v){
42         ContentValues c = new ContentValues();
43         c.put("name", "user222");
44         c.put("password", "88888888");
45         db.update("user", c, "id=?", new String[]{"2"});
46     }
47     public void query(View v){
48         String[] colums = {"id", "name", "password"};
49         Cursor c = db.query("user", colums, null, null, null, null, null);
50
51         while(c.moveToNext()){
52             int id = c.getInt(c.getColumnIndex("id"));
53             String username = c.getString(c.getColumnIndex("name"));
54             String password = c.getString(c.getColumnIndex("password"));
55             Log.i("sqliteopenhelper", id + "," +username+"," +password);
56         }
57     }
58 }

MainActivity.java