006_02SQLite_OpenHelper

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

 

006_02SQLite_OpenHelper

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