Android：SQLite添加數據時出錯

我正在開發一款PiggyBank應用程序，其中用戶可以製作他們想要的物品的願望清單並幫助他們保存該物品。我的應用程序仍然處於原型，因爲我仍然在學習android。Android：SQLite添加數據時出錯

我現在遇到的問題是每次我添加新的數據時，它總是返回false。這裏是我的代碼：

DatabaseHelper.java

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.DatabaseErrorHandler; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.util.Log; 


public class DatabaseHelper extends SQLiteOpenHelper { 

private static final String TAG = "DatabaseHelper"; 

private static final String TABLE_NAME = "people_table"; 
private static final String COL1 = "ID"; 
private static final String COL2 = "name"; 
private static final String COL3 = "price"; 
private static final String COL4 = "totalsavings"; 
private static final String COL5 = "duedate"; 


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

@Override 
public void onCreate(SQLiteDatabase db) { 
    String createTable = "CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, " + 
      COL2 +" TEXT, " + COL3 + "TEXT, " + COL4 +"INTEGER)"; 
    db.execSQL(createTable); 
} 

@Override 
public void onUpgrade(SQLiteDatabase db, int i, int i1) { 
    db.execSQL("DROP IF TABLE EXISTS " + TABLE_NAME); 
    onCreate(db); 
} 

public boolean addData(String item) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    ContentValues contentValues = new ContentValues(); 
    contentValues.put(COL2, item); 
    contentValues.put(COL3, item); 
    contentValues.put(COL4, item); 

    Log.d(TAG, "addData: Adding " + item + " to " + TABLE_NAME); 

    long result = db.insert(TABLE_NAME, null, contentValues); 

    //if date as inserted incorrectly it will return -1 
    if (result == -1) { 
     return false; 
    } else { 
     return true; 
    } 
} 

/** 
* Returns all the data from database 
* @return 
*/ 
public Cursor getData(){ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    String query = "SELECT * FROM " + TABLE_NAME; 
    Cursor data = db.rawQuery(query, null); 
    return data; 
} 

/** 
* Returns only the ID that matches the name passed in 
* @param name 
* @return 
*/ 
public Cursor getItemID(String name){ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    String query = "SELECT " + COL1 + " FROM " + TABLE_NAME + 
      " WHERE " + COL2 + " = '" + name + "'"; 
    Cursor data = db.rawQuery(query, null); 
    return data; 
} 

/** 
* Updates the name field 
* @param newName 
* @param id 
* @param oldName 
*/ 
public void updateName(String newName, int id, String oldName){ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    String query = "UPDATE " + TABLE_NAME + " SET " + COL2 + 
      " = '" + newName + "' WHERE " + COL1 + " = '" + id + "'" + 
      " AND " + COL2 + " = '" + oldName + "'"; 
    Log.d(TAG, "updateName: query: " + query); 
    Log.d(TAG, "updateName: Setting name to " + newName); 
    db.execSQL(query); 
} 

/** 
* Delete from database 
* @param id 
* @param name 
*/ 
public void deleteName(int id, String name){ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    String query = "DELETE FROM " + TABLE_NAME + " WHERE " 
      + COL1 + " = '" + id + "'" + 
      " AND " + COL2 + " = '" + name + "'"; 
    Log.d(TAG, "deleteName: query: " + query); 
    Log.d(TAG, "deleteName: Deleting " + name + " from database."); 
    db.execSQL(query); 
} 

}

MainActivity.java

import android.content.Intent; 
    import android.support.v7.app.AppCompatActivity; 
    import android.os.Bundle; 
    import android.view.View; 
    import android.widget.Button; 
    import android.widget.EditText; 
    import android.widget.Toast; 

public class MainActivity extends AppCompatActivity { 

private static final String TAG = "MainActivity"; 

DatabaseHelper mDatabaseHelper; 
private Button btnAdd, btnViewData; 
private EditText editText, editText2; 

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

    //for inputs 
    editText = (EditText) findViewById(R.id.editText); 
    editText2 =(EditText) findViewById(R.id.editText2); 

    //buttons 
    btnAdd = (Button) findViewById(R.id.btnAdd); 
    btnViewData = (Button) findViewById(R.id.btnView); 

    //call database 
    mDatabaseHelper = new DatabaseHelper(this); 

    btnAdd.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      String newEntry = editText.getText().toString(); 
      if (editText.length() != 0) { 
       AddData(newEntry); 
       editText.setText(""); 
      } else { 
       toastMessage("You must put something in the text field!"); 
      } 

      String newPriceEntry = editText2.getText().toString(); 
      if (editText2.length() != 0) { 
       AddData(newPriceEntry); 
       editText2.setText(""); 
      } else { 
       toastMessage("You must put something in the text field!"); 
      } 

     } 
    }); 

    btnViewData.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Intent intent = new Intent(MainActivity.this, ListDataActivity.class); 
      startActivity(intent); 
     } 
    }); 

} 

public void AddData(String newEntry) { 
    boolean insertData = mDatabaseHelper.addData(newEntry); 

    if (insertData) { 
     toastMessage("Data Successfully Inserted!"); 
    } else { 
     toastMessage("Something went wrong"); 
    } 
} 

/** 
* customizable toast 
* @param message 
*/ 
private void toastMessage(String message){ 
    Toast.makeText(this,message, Toast.LENGTH_SHORT).show(); 
} 
}

ListDataActivity.java

import android.content.Intent; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.support.annotation.Nullable; 
import android.support.v7.app.AppCompatActivity; 
import android.util.Log; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.Toast; 

import java.util.ArrayList; 

/** 
* Created by User on 2/28/2017. 
*/ 

public class ListDataActivity extends AppCompatActivity { 

private static final String TAG = "ListDataActivity"; 

DatabaseHelper mDatabaseHelper; 

private ListView mListView; 

@Override 
protected void onCreate(@Nullable Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.list_layout); 
    mListView = (ListView) findViewById(R.id.listView); 
    mDatabaseHelper = new DatabaseHelper(this); 

    populateListView(); 
} 

private void populateListView() { 
    Log.d(TAG, "populateListView: Displaying data in the ListView."); 

    //get the data and append to a list 
    Cursor data = mDatabaseHelper.getData(); 
    ArrayList<String> listData = new ArrayList<>(); 
    while(data.moveToNext()){ 
     //get the value from the database in column 1 
     //then add it to the ArrayList 
     listData.add(data.getString(1)); 

    } 
    //create the list adapter and set the adapter 
    ListAdapter adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, listData); 
    mListView.setAdapter(adapter); 

    //set an onItemClickListener to the ListView 
    mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) { 
      String name = adapterView.getItemAtPosition(i).toString(); 
      Log.d(TAG, "onItemClick: You Clicked on " + name); 

      Cursor data = mDatabaseHelper.getItemID(name); //get the id associated with that name 
      int itemID = -1; 
      while(data.moveToNext()){ 
       itemID = data.getInt(0); 
      } 
      if(itemID > -1){ 
       Log.d(TAG, "onItemClick: The ID is: " + itemID); 
       Intent editScreenIntent = new Intent(ListDataActivity.this, EditDataActivity.class); 
       editScreenIntent.putExtra("id",itemID); 
       editScreenIntent.putExtra("name",name); 
       startActivity(editScreenIntent); 
      } 
      else{ 
       toastMessage("No ID associated with that name"); 
      } 
     } 
    }); 
} 

/** 
* customizable toast 
* @param message 
*/ 
private void toastMessage(String message){ 
    Toast.makeText(this,message, Toast.LENGTH_SHORT).show(); 
    } 
}

EditDataActivity.java 在此活動中，數據將顯示在EditText（名稱）儲蓄目標（價格）中。（我仍在努力完成總計）。

import android.content.DialogInterface; 
import android.content.Intent; 
import android.os.Bundle; 
import android.support.annotation.Nullable; 
import android.support.v7.app.AlertDialog; 
import android.support.v7.app.AppCompatActivity; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 
import android.widget.Toast; 



public class EditDataActivity extends AppCompatActivity { 

private static final String TAG = "EditDataActivity"; 

private TextView myGoal, mySavings; 
private Button btnSave,btnDelete, btnDeposit; 
private EditText editable_item, depositInput; 

DatabaseHelper mDatabaseHelper; 

private String selectedName, selectedPrice; 
private int selectedID, selectedTotalSavings; 

@Override 
protected void onCreate(@Nullable Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.edit_data_layout); 

    myGoal = (TextView) findViewById(R.id.displayGoal); 
    mySavings = (TextView) findViewById(R.id.displayTotalSavings); 

    btnSave = (Button) findViewById(R.id.btnSave); 
    btnDelete = (Button) findViewById(R.id.btnDelete); 
    btnDeposit = (Button) findViewById(R.id.btnDeposit); 

    editable_item = (EditText) findViewById(R.id.editable_item); 
    mDatabaseHelper = new DatabaseHelper(this); 

    //get the intent extra from the ListDataActivity 
    Intent receivedIntent = getIntent(); 

    //now get the itemID we passed as an extra 
    selectedID = receivedIntent.getIntExtra("id",-1); //NOTE: -1 is just the default value 

    //now get the name we passed as an extra 
    selectedName = receivedIntent.getStringExtra("name"); 

    //now get the price we passed as an extra 
    selectedPrice = receivedIntent.getStringExtra("price"); 

    //now we get the totalsavings we passed as an extra 
    selectedTotalSavings = receivedIntent.getIntExtra("totalsavings", -1); 

    //set the text to show the current selected name 
    editable_item.setText(selectedName); 

    //set the text to show the user's saving goal 
    myGoal.setText(selectedPrice); 

    //set text to show the user's total savings so far 
    mySavings.setText(selectedTotalSavings); 

     //-----------------------------------DIALOG BOX----------------------------------------- 
     AlertDialog.Builder builder = new AlertDialog.Builder(this); 
     builder.setTitle("Enter Deposit"); 
     builder.setMessage("Enter your deposit!"); 

     depositInput= new EditText(this); 
     builder.setView(depositInput); 

      //SET POSITIVE BUTTON 
       builder.setPositiveButton("Submit", new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface dialog, int which) { 
         String depositTxt=depositInput.getText().toString(); 

         selectedTotalSavings = Integer.parseInt(selectedTotalSavings + depositTxt); 
         mySavings.setText(selectedTotalSavings); 
         Toast.makeText(getApplicationContext(),depositTxt, Toast.LENGTH_LONG).show(); 
        } 
       }); 

      //SET NEGATIVE BUTTON 
    builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
     @Override 
     public void onClick(DialogInterface dialog, int which) { 
      dialog.dismiss(); 
     } 
    }); 

      //CREATE THE DIALOG 
      final AlertDialog depositPrompt=builder.create(); 

     //-------------------------------------------------------------------------------------- 

    //buttons 
    btnSave.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      String item = editable_item.getText().toString(); 
      if(!item.equals("")){ 
       mDatabaseHelper.updateName(item,selectedID,selectedName); 
      }else{ 
       toastMessage("You must enter a name"); 
      } 
     } 
    }); 

    btnDelete.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      mDatabaseHelper.deleteName(selectedID,selectedName); 
      editable_item.setText(""); 
      toastMessage("removed from database"); 
     } 
    }); 

    btnDeposit.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View arg0){ 
      depositPrompt.show(); 


     } 
    }); 

} 

/** 
* customizable toast 
* @param message 
*/ 
private void toastMessage(String message){ 
    Toast.makeText(this,message, Toast.LENGTH_SHORT).show(); 
    } 
}

這裏的語法示例

用戶輸入的名稱和價格的詳細信息
用戶單擊Add數據
用戶可以查看數據，數據將在一個ListView
用戶可以編輯和查看EditDataActivity中的數據

我不確定是什麼問題。

UPDATE

，所以我發現在MainActivity類此代碼。我試圖從editText2添加數據，但我不知道如何。

btnAdd.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      String newEntry = editText.getText().toString(); 
      if (editText.length() != 0) { 
       AddData(newEntry); 
       editText.setText(""); 
      } else { 
       toastMessage("You must put something in the text field!"); 
      } 

      String newPriceEntry = editText2.getText().toString(); 
      if (editText2.length() != 0) { 
       AddData(newPriceEntry); 
       editText2.setText(""); 
      } else { 
       toastMessage("You must put something in the text field!"); 
      } 

     } 
    }); 

    btnViewData.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Intent intent = new Intent(MainActivity.this, ListDataActivity.class); 
      startActivity(intent); 
     } 
    }); 

} 

public void AddData(String newEntry) { 
    boolean insertData = mDatabaseHelper.addData(newEntry); 

    if (insertData) { 
     toastMessage("Data Successfully Inserted!"); 
    } else { 
     toastMessage("Something went wrong"); 
    } 
}

我必須做一個新的AddData嗎？

來源

2017-04-13 Jonathan Melendrez

使用ormlite而不是源碼快速操作 –

你需要插入正確類型值，如下所述：

public boolean addData(String item) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    ContentValues contentValues = new ContentValues(); 
    contentValues.put(COL2, item); 
    contentValues.put(COL3, item); 
    contentValues.put(COL4, item); // pass an integer instead of a String as you have mentioned its datatype as INTEGER or parse it using Integer.parseInt() 

    Log.d(TAG, "addData: Adding " + item + " to " + TABLE_NAME); 

    long result = db.insert(TABLE_NAME, null, contentValues); 

    //if date as inserted incorrectly it will return -1 
    if (result == -1) { 
     return false; 
    } else { 
     return true; 
    } 
}

來源

2017-04-13 04:56:53

（https://sqlite.org/datatype3.html）。 *「在SQLite中，值的數據類型與值本身相關聯，而不與其容器相關聯。」* – Abbas

我認爲這個問題是在CREATE TABLE查詢。

String createTable = "CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, " + COL2 +" TEXT, " + COL3 + "TEXT, " + COL4 +"INTEGER)";

有（對於COL4和"INTEGER"相同）COL3和"TEXT"之間沒有空格。所以只需添加一個像這樣的空間。

String createTable = "CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, " + COL2 +" TEXT, " + COL3 + " TEXT, " + COL4 +" INTEGER)";

來源

2017-04-13 04:58:43 Abbas

問題出在您的addData()方法中。 COL4保存INTEGER的值。

試試這個：

public boolean addData(String item) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    ContentValues contentValues = new ContentValues(); 
    contentValues.put(COL2, item); 
    contentValues.put(COL3, item); 
    contentValues.put(COL4, Integer.parseInt(item)); 

    Log.d(TAG, "addData: Adding " + item + " to " + TABLE_NAME); 

    long result = db.insert(TABLE_NAME, null, contentValues); 

    //if date as inserted incorrectly it will return -1 
    if (result == -1) { 
     return false; 
    } else { 
     return true; 
    } 
}

來源

2017-04-13 05:00:50 FAT

db.insert的（）的返回是一個漫長而你比較它與一個int。實際上根據[此]變更

if (result == -1) { 
    return false; 
} else { 
    return true; 
}

要

return (int)result == -1;

來源

2017-04-13 05:13:31 KoalaStorm

Android：SQLite添加數據時出錯

回答

相關問題