android에서 SQLite로부터 데이터를 가져오고 표시하는 방법

Question

나는 username과 passWord를 가져 오기 위해 어떤 실수를했는지 혼란 스럽네요. (여기 새로 왔고 android에 대해 :) 정말 미안하다. 질문) 다음은, 임의 업데이트시 아래 다음 전화를 삭제하거나 쿼리를 삽입해야

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
import android.widget.Toast; 

public class LoginDataBaseAdapter 
{ 
    static final String DATABASE_NAME = "login.db"; 
    static final int DATABASE_VERSION = 1; 
    public static final int NAME_COLUMN = 1; 
    // TODO: Create public field for each column in your table. 
    // SQL Statement to create a new database. 
    static final String DATABASE_CREATE = "create table "+"LOGIN"+ "(" +"ID"+" integer primary key autoincrement,"+ "USERNAME text,PASSWORD text,MOBILENO int); "; 
    // Variable to hold the database instance 
    public SQLiteDatabase db; 
    // Context of the application using the database. 
    private final Context context; 
    // Database open/upgrade helper 
    private DataBaseHelper dbHelper; 
    public LoginDataBaseAdapter(Context _context) 
    { 
     context = _context; 
     dbHelper = new DataBaseHelper(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 
    public LoginDataBaseAdapter open() throws SQLException 
    { 
     db = dbHelper.getWritableDatabase(); 
     return this; 
    } 
    public void close() 
    { 
     db.close(); 
    } 

    public SQLiteDatabase getDatabaseInstance() 
    { 
     return db; 
    } 

    public void insertEntry(String userName,String password,String mobileNumber) 
    { 
     ContentValues newValues = new ContentValues(); 
     // Assign values for each row. 
     newValues.put("USERNAME", userName); 
     newValues.put("PASSWORD", password); 
     newValues.put("MOBILENO", mobileNumber); 

     // Insert the row into your table 
     db.insert("LOGIN", null, newValues); 
     //Toast.makeText(context, "Reminder Is Successfully Saved", Toast.LENGTH_LONG).show(); 
    } 
    public int deleteEntry(String UserName) 
    { 
     //String id=String.valueOf(ID); 
     String where="USERNAME=?"; 
     int numberOFEntriesDeleted= db.delete("LOGIN", where, new String[]{UserName}) ; 
     Toast.makeText(context, "Number fo Entry Deleted Successfully : "+numberOFEntriesDeleted, Toast.LENGTH_LONG).show(); 
     return numberOFEntriesDeleted; 
    } 
    public String getSingleEntry(String userName) 
    { 
     Cursor cursor=db.query("LOGIN", null, " USERNAME=?", new String[]{userName}, null, null, null); 
     if(cursor.getCount()<1) // UserName Not Exist 
     { 
      cursor.close(); 
      return "NOT EXIST...!!!"; 
     } 
     cursor.moveToFirst(); 
     String password= cursor.getString(cursor.getColumnIndex("PASSWORD")); 
     // String mobileNumber=cursor.getString(cursor.getColumnIndex("MOBILENO")); 
     cursor.close(); 
     return "Password="+password; 

    } 
    public void updateEntry(String userName,String password,String mobileNumber) 
    { 
     // Define the updated row content. 
     ContentValues updatedValues = new ContentValues(); 
     // Assign values for each row. 
     updatedValues.put("USERNAME", userName); 
     updatedValues.put("PASSWORD", password); 
     updatedValues.put("MOBILENO", mobileNumber); 

     String where="USERNAME = ?"; 
     db.update("LOGIN",updatedValues, where, new String[]{userName});    
    }   
} 

LoginDatabaseAdapter.java

및 SignupActivity.java

import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 
import android.widget.Toast; 

public class SignUpActivity extends Activity 
{ 
EditText  editTextUserName,editTextPassword,editTextConfirmPassword,editTextMobileNo; 
Button btnCreateAccount; 

Button btnfetch; 
TextView sv; 

LoginDataBaseAdapter loginDataBaseAdapter; 
@Override 
protected void onCreate(Bundle savedInstanceState) 
{ 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.signup); 

    // get Instance of Database Adapter 
    loginDataBaseAdapter=new LoginDataBaseAdapter(this); 
    loginDataBaseAdapter=loginDataBaseAdapter.open(); 

    // Get Refferences of Views 
    editTextUserName=(EditText)findViewById(R.id.editTextUserName); 
    editTextPassword=(EditText)findViewById(R.id.editTextPassword); 
    editTextConfirmPassword=(EditText)findViewById(R.id.editTextConfirmPassword); 
    editTextMobileNo=(EditText)findViewById(R.id.editTextMobileNo); 

    btnCreateAccount=(Button)findViewById(R.id.buttonCreateAccount); 
    btnCreateAccount.setOnClickListener(new View.OnClickListener() { 

    public void onClick(View v) { 
     // TODO Auto-generated method stub 

     String userName=editTextUserName.getText().toString(); 
     String password=editTextPassword.getText().toString(); 
     String confirmPassword=editTextConfirmPassword.getText().toString(); 
     String mobileNumber=editTextMobileNo.getText().toString(); 

     // check if any of the fields are vaccant 
     if(userName.equals("")||password.equals("")||confirmPassword.equals("")||mobileNumber.equals("")) 
     { 
       Toast.makeText(getApplicationContext(), "Please Enter Your Details", Toast.LENGTH_LONG).show(); 
       return; 
     } 
     // check if both password matches 
     if(!password.equals(confirmPassword)) 
     { 
      Toast.makeText(getApplicationContext(), "Confirm Password does not match", Toast.LENGTH_LONG).show(); 
      return; 
     } 
     else 
     { 
      // Save the Data in Database 
      loginDataBaseAdapter.insertEntry(userName, password,mobileNumber); 
      Toast.makeText(getApplicationContext(), "Account Successfully Created ", Toast.LENGTH_LONG).show(); 
     } 
    } 
}); 

    btnfetch=(Button)findViewById(R.id.btnshow); 
    btnfetch.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      sv=(TextView)findViewById(R.id.tvshow); 
      String userName=editTextUserName.getText().toString(); 
      String pass=loginDataBaseAdapter.getSingleEntry(userName); 
      sv.setText(pass); 
     } 
    }); 

} 
@Override 
protected void onDestroy() { 
    // TODO Auto-generated method stub 
    super.onDestroy(); 

    loginDataBaseAdapter.close(); 
} 
} 

Answer 1

입니다. 아래

db.beginTransaction(); 
try { 
    // CALL insert, update or delete 
    db.setTransactionSuccessful(); 
} catch { 
    //Error in between database transaction 
} finally { 
    db.endTransaction(); 
} 

예 :

ContentValues newValues = new ContentValues(); 
newValues.put("USERNAME", userName); 
newValues.put("PASSWORD", password); 
newValues.put("MOBILENO", mobileNumber); 

db.beginTransaction(); 
try {  
    // Insert the row into your table 
    db.insert("LOGIN", null, newValues); 
    db.setTransactionSuccessful(); 
} catch { 
    //Error in between database transaction 
} finally { 
    db.endTransaction(); 
} 

Answer 2

나는 당신이 당신의 LoginDataBaseAdapter 클래스의 DATABASE_CREATE 명령을 가지고 볼 수 있지만, 임의의 장소에서 사용하지 않는 것. 실제로 데이터베이스에 LOGIN 테이블을 만드시겠습니까? (그 내용은 제공하지 않았다) 귀하의 DataBaseHelper 클래스는 다음과 같이 포함되어야합니다

@Override 
public void onCreate(SQLiteDatabase db) { 
    db.execSQL(LoginDataBaseAdapter.DATABASE_CREATE); 
} 

onCreate 방법은 데이터베이스가 처음 만들어 질 때 호출되는, 그래서 당신이 먼저 이전 데이터베이스를 삭제해야합니다. (응용 프로그램을 제거하면 문제가 해결됩니다.)

logcat에서 복사 한 예외 스택 추적 (있는 경우)을 포함하여 어떤 오류가 발생했는지에 대한 자세한 정보를 제공하십시오.