android.database.sqlite.SQLiteException：near "productname"：構文エラー（コード1）：コンパイル中：

Question

私のアプリケーションでデータベースを作成しようとしています。残念ながら、私はいくつかの問題を実行して私のアプリを実行しています。

DbHandlerクラス：

package com.example.jarno.a49_savingdata; 

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

/** 
* Created by jarno on 24-1-17. 
*/ 

public class MyDbHandler extends SQLiteOpenHelper { 

    private static final int DATABASE_VERSION = 1; 
    private static final String DATABASE_NAME = "products.db"; 
    public static final String TABLE_PRODUCTS = "products"; 
    public static final String COLUMN_ID = "_id"; 
    public static final String COLUMN_PRODUCTNAME = "productname"; 

    public MyDbHandler(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) { 
     super(context, name, factory, version); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" + 
       COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT " + 
       COLUMN_PRODUCTNAME + " TEXT " + 
       ");"; 
     db.execSQL(query); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     db.execSQL("DROP_TABLE_IF_EXISTS" + TABLE_PRODUCTS); 
     onCreate(db); 
    } 

    public void addProduct(Products product) { 
     ContentValues values = new ContentValues(); 
     values.put(COLUMN_PRODUCTNAME, product.get_productname()); 
     SQLiteDatabase db = getWritableDatabase(); 
     db.insert(TABLE_PRODUCTS, null, values); 
     db.close(); 
    } 

    public void delProduct(String productName) { 
     SQLiteDatabase db = getWritableDatabase(); 
     db.execSQL("DELETE FROM " + TABLE_PRODUCTS + " WHERE " + COLUMN_PRODUCTNAME + "=\"" + productName + "\";"); 
    } 

    public String databaseToString() { 
     String dbString = ""; 
     SQLiteDatabase db = getWritableDatabase(); 
     String query = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE 1"; 

     // Cursor point to a location in the results 
     Cursor c = db.rawQuery(query, null); 
     // Move to the first row in the results 
     c.moveToFirst(); 

     while(!c.isAfterLast()) { 
      if(c.getString(c.getColumnIndex("productname")) != null) { 
       dbString += c.getString(c.getColumnIndex("productname")); 
       dbString += "\n"; 
      } 
     } 
     db.close(); 
     return dbString; 
    } 
} 

がエラー：

FATAL EXCEPTION: main 
               Process: com.example.jarno.a49_savingdata, PID: 4115 
               java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.jarno.a49_savingdata/com.example.jarno.a49_savingdata.MainActivity}: android.database.sqlite.SQLiteException: near "productname": syntax error (code 1): , while compiling: CREATE TABLE products(_id INTEGER PRIMARY KEY AUTOINCREMENT productname TEXT): 
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665) 
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
                at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
                at android.os.Handler.dispatchMessage(Handler.java:102) 
                at android.os.Looper.loop(Looper.java:154) 
                at android.app.ActivityThread.main(ActivityThread.java:6119) 
                at java.lang.reflect.Method.invoke(Native Method) 
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 
                Caused by: android.database.sqlite.SQLiteException: near "productname": syntax error (code 1): , while compiling: CREATE TABLE products(_id INTEGER PRIMARY KEY AUTOINCREMENT productname TEXT): 
                at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method) 
                at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889) 
                at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500) 
                at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588) 
                at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58) 
                at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31) 
                at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1677) 
                at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1608) 
                at com.example.jarno.a49_savingdata.MyDbHandler.onCreate(MyDbHandler.java:31) 
                at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:251) 
                at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163) 
                at com.example.jarno.a49_savingdata.MyDbHandler.databaseToString(MyDbHandler.java:55) 
                at com.example.jarno.a49_savingdata.MainActivity.printDatabase(MainActivity.java:40) 
                at com.example.jarno.a49_savingdata.MainActivity.onCreate(MainActivity.java:23) 
                at android.app.Activity.performCreate(Activity.java:6679) 
                at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618) 
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)  
                at android.app.ActivityThread.-wrap12(ActivityThread.java)  
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)  
                at android.os.Handler.dispatchMessage(Handler.java:102)  
                at android.os.Looper.loop(Looper.java:154)  
                at android.app.ActivityThread.main(ActivityThread.java:6119)  
                at java.lang.reflect.Method.invoke(Native Method)  
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)  
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)  

私はこのコードで何か問題がなければならないと思いますが、私は何を見つけることができません。

"CREATE TABLE " + TABLE_PRODUCTS + "(" + 
       COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT " + 
       COLUMN_PRODUCTNAME + " TEXT " + 
       ");"; 

Answer 1

AUTOINCREMENTの後ろにコンマを入れて、新しい列を宣言するとき

COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +