SQLite數據庫沒有插入值

Question

該項目由兩個類組成，一個用於主要活動，另一個用於擴展Sqliteopenhelper類以便在數據庫上執行查詢的數據庫幫助程序類。添加數據按鈕不會將數據插入數據庫時​​發生問題。可能，「插入數據」方法有問題，我無法弄清楚。或者是別的什麼？

MainActivity.java

public class MainActivity extends Activity { 
DatabaseHelper myDb; 
EditText editName,editF1,editF2,editF3,editF4,editF5; 
Button btnAddData; 
Button btnViewAll; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    myDb = new DatabaseHelper(this); 

    editName = (EditText)findViewById(R.id.editText_name); 
    editF1 = (EditText)findViewById(R.id.editText_F1); 
    editF2 = (EditText)findViewById(R.id.editText_F2); 
    editF3= (EditText)findViewById(R.id.editText_F3); 
    editF4= (EditText)findViewById(R.id.editText_F4); 
    editF5= (EditText)findViewById(R.id.editText_F5); 
    btnAddData = (Button)findViewById(R.id.button_add); 
    btnViewAll = (Button)findViewById(R.id.button_viewAll); 
    AddData(); 
    viewAll(); 
} 
public void AddData() { 
    btnAddData.setOnClickListener(
      new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        boolean isInserted = 
myDb.insertData(editName.getText().toString(), editF1.getText().toString(), 
editF2.getText().toString(), editF3.getText().toString(), 
editF4.getText().toString(), editF5.getText().toString()); 
        if(isInserted == true) 
         Toast.makeText(MainActivity.this,"Data 
Inserted",Toast.LENGTH_LONG).show(); 
        else 
         Toast.makeText(MainActivity.this,"Data not 
Inserted",Toast.LENGTH_LONG).show(); 
       } 
      } 
    ); 
} 

public void viewAll() { 
    btnViewAll.setOnClickListener(
      new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        Cursor res = myDb.getAllData(); 
        if(res.getCount() == 0) { 
         // show message 
         showMessage("Error","Nothing found"); 
         return; 
        } 

        StringBuffer buffer = new StringBuffer(); 
        while (res.moveToNext()) { 
         buffer.append("Name :"+ res.getString(0)+"\n"); 
         buffer.append("Teaching Skills :"+ 
res.getString(1)+"\n"); 
         buffer.append("Competency :"+ 
res.getString(2)+"\n"); 
         buffer.append("Approachability :"+ 
res.getString(3)+"\n"); 
         buffer.append("Class Control :"+ 
res.getString(4)+"\n"); 
         buffer.append("Punctuality :"+ 
res.getString(5)+"\n\n"); 
        } 

        // Show all data 
        showMessage("Data",buffer.toString()); 
       } 
      } 
    ); 
} 

public void showMessage(String title,String Message){ 
    AlertDialog.Builder builder = new AlertDialog.Builder(this); 
    builder.setCancelable(true); 
    builder.setTitle(title); 
    builder.setMessage(Message); 
    builder.show(); 
} 
} 

DatabaseHelper.java

package com.dot.myapplication; 
import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 

public class DatabaseHelper extends SQLiteOpenHelper { 
public static final String DATABASE_NAME = "Student.db"; 
public static final String TABLE_NAME = "student_table"; 
public static final String COL_2 = "NAME"; 
public static final String COL_3 = "F1"; 
public static final String COL_4 = "F2"; 
public static final String COL_5 = "F3"; 
public static final String COL_6 = "F4"; 
public static final String COL_7 = "F5"; 

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

@Override 
public void onCreate(SQLiteDatabase db) { 
    db.execSQL("create table " + TABLE_NAME +" (NAME TEXT,F1 TEXT,F2 TEXT,F3 
TEXT,F4 TEXT,F5 TEXT)"); 
} 

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

public boolean insertData(String name,String F1s,String F2s,String 
F3s,String F4s,String F5s) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    ContentValues contentValues = new ContentValues(); 
    contentValues.put(COL_2,name); 
    contentValues.put(COL_3,F1s); 
    contentValues.put(COL_4,F2s); 
    contentValues.put(COL_5,F3s); 
    contentValues.put(COL_6,F4s); 
    contentValues.put(COL_7,F5s); 
    long result = db.insert(TABLE_NAME,null ,contentValues); 
    if(result == -1) 
     return false; 
    else 
     return true; 
} 

public Cursor getAllData() { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    Cursor res = db.rawQuery("select * from " + TABLE_NAME, null); 
    return res; 
} 
} 

每當添加數據按鈕時沒有插入敬酒被調用數據。作爲初學者，我無法弄清楚哪裏出了問題。這是insertData方法的東西嗎？請建議更改。

Answer 1

您的插入是正確的。你必須像這樣查詢數據。

   if(res.moveToFirst()){ 
         do{ 
          buffer.append("Name :"+ res.getString(0)+"\n"); 
          buffer.append("Teaching Skills :"+ res.getString(1)+"\n"); 
          buffer.append("Competency :"+ res.getString(2)+"\n"); 
          buffer.append("Approachability :"+ res.getString(3)+"\n"); 
          buffer.append("Class Control :"+ res.getString(4)+"\n"); 
          buffer.append("Punctuality :"+ res.getString(5)+"\n\n"); 
         }while (res.moveToNext()) 
      } 

在你數據庫輔助類，你忘了接近查詢數據庫之後。

這裏是學習SQLite數據庫實現的完美教程。 http://www.techotopia.com/index.php/An_Android_SQLite_Database_Tutorial