如何在按钮点击数据库中添加数据？

Question

我是新来的Android以下是我的代码，我希望在数据基础上添加按钮的点击数据，但是当我按一下按钮我的应用程序崩溃 任何人可以建议我任何解决方案 这里是我的代码：

public class Third extends Activity implements OnClickListener{ 
Button btn; 
SQLiteDatabase db; 
EditText edit1; 
EditText edit2; 
EditText edit3; 

@Override 
protected void onCreate(Bundle icicle) { 
// TODO Auto-generated method stub 
super.onCreate(icicle); 
setContentView(R.layout.mit); 
SQLiteDatabase db; 
db = openOrCreateDatabase("doctorinfo.db", SQLiteDatabase.CREATE_IF_NECESSARY, null); 
db.setVersion(1); 
db.setLocale(Locale.getDefault()); 
db.setLockingEnabled(true); 
final String CREATE_TABLE_COUNTRIES ="CREATE TABLE med_d ("+ "id INTEGER PRIMARY KEY AUTOINCREMENT,"+ "DOC_NAME TEXT,"+ "DOC_NO TEXT,"+ "DOC_EMAIL TEXT);"; 
//db.execSQL(CREATE_TABLE_COUNTRIES); 
btn=(Button)findViewById(R.id.button1); 
edit1=(EditText)findViewById(R.id.editText1); 
edit2=(EditText)findViewById(R.id.editText2); 
edit3=(EditText)findViewById(R.id.editText3); 

btn.setOnClickListener(this); 


} 

@Override 
public void onClick(View arg0) { 
String d=edit1.getText().toString(); 
String m=edit2.getText().toString(); 
String p=edit3.getText().toString(); 

ContentValues values = new ContentValues(); 
values.put("DOC_NAME",d); 
values.put("DOC_NO",m); 
values.put("DOC_EMAIL",p); 
//long countryId = db.insert("med_d", null, values); 
//try { 
db.insertOrThrow("med_d", null,values); 
}// catch (Exception e) { 
//Log.e("Add Error", e.toString()); 
//e.printStackTrace(); 
//} 



} 

Answer 1

SQLITEOPENHELPER CLASS

package com.db.demo; 


import android.content.Context; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.provider.BaseColumns; 

/** 
* Subclass of the {@link SQLiteOpenHelper} that sets up the database for the 
* demo. 
* 
* @author Kah 
*/ 
public class DatabaseHelper extends SQLiteOpenHelper { 

public DatabaseHelper(Context context) { 
    super(context, "CursorDemo", null, 1); 
} 

@Override 
public void onCreate(SQLiteDatabase db) { 
    db.execSQL("CREATE TABLE IF NOT EXISTS names (" 
      + BaseColumns._ID 
      + " INTEGER PRIMARY KEY AUTOINCREMENT, first VARCHAR, last VARCHAR)"); 
    db.execSQL("INSERT INTO names (first, last) VALUES ('John', 'Doe')"); 
    db.execSQL("INSERT INTO names (first, last) VALUES ('James', 'Kirk')"); 
} 

@Override 
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    // Steps to upgrade the database for the new version ... 
} 

}

**** Activity类****

package com.db.demo; 


import android.app.ListActivity; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.os.Bundle; 
import android.provider.BaseColumns; 
import android.widget.CursorAdapter; 
import android.widget.ListView; 
import android.widget.SimpleCursorAdapter; 

public class DataHandlingActivity extends ListActivity{ 
    private SQLiteDatabase database; 
String fields[] = { "first", "last", BaseColumns._ID }; 
    private CursorAdapter dataSource; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    DatabaseHelper helper = new DatabaseHelper(this); 
    database = helper.getReadableDatabase(); 
    Cursor data = database.query("names", fields, null, null, null, null, 
      null); 

    dataSource = new SimpleCursorAdapter(this, R.layout.row, data, fields, 
      new int[] { R.id.first, R.id.last }); 

    ListView view = getListView(); 
    view.setHeaderDividersEnabled(true); 
    view.addHeaderView(getLayoutInflater().inflate(R.layout.row, null)); 

    setListAdapter(dataSource); 
} 

}

使用像这样的按钮，点击更改活动类 update sql database with ContentValues and the update-method

Answer 2

你必须使用SqliteOpenHelper类来完成所有的数据库操作。

请通过这个链接，这会给你一些很好的提示。

http://www.xoriant.com/blog/mobile-application-development/android-sqlite-database.html

Answer 3

将这个方法在数据库中的辅助类：

public long InsertRecord(String msg, String msg1,String msg2) { 

    long d = 0; 
    ContentValues values = new ContentValues(); 

    values.put(SMS_NO, msg); 
    values.put(SMS_BODY, msg1); 
      values.put(SMS_BODY, msg2); 

    try { 
     d = myDataBase.insert(SMS_TBL, null, values); 
    } catch (Exception e) { 

    } 
    return d; 

} 

在此之后

在活动的onCreate方法，你必须把这个代码来创建thedatabase：

SQLiteDatabase sqLiteDatabase; 
DataBaseHelper dbHelper; 

dbHelper = new DataBaseHelper(getActivity().getApplicationContext()); 


      try { 
       dbHelper.createDataBase(); 
      } catch (IOException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 

      dbHelper.openDataBase(); 
       dbHelper.onCreate(sqLiteDatabase); 

最后在上btn点击

btnBlock.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      String edittext = edittext.getText().toString(); 
      String edittext1 = edittext1.getText().toString(); 
          String edittext2 = edittext2.getText().toString(); 

      dbHelper.InsertRecord(edittext,edittext1,edittext2); 

     } 
    });