java - sqlite 数据库的 on create 方法中出现错误

Question

我正在为类作业创建一个问答游戏。我最初想将问题与类别存储在 sqlite 数据库中。我正在使用一张表，尽管我想为类别、级别和用户添加其他表，但首先想让它仅处理问题。该程序编译并安装到模拟器中，第一部分工作正常。直到应用程序创建数据库时我才收到错误。错误如下:

原因:

android.database.sqlite.SQLiteException: near "TABLEquestion": syntax error (code 1): , while compiling: CREATE TABLEquestion(questionIDINTEGER PRIMARY KEY,questionNameTEXT,optionATEXT,optionBTEXT,optionCTEXT,answerTEXT,questionLevelIDINTEGER,categoryIDINTEGER)
                                                                                           at android.database.sqlite

我的主要 Activity 、琐事问题 Activity 、问题类、DBHelper 类以及琐事问题 Activity 的 xml 布局的代码。请注意，当为类别选择单选按钮并启动琐事问题 Activity 时，会发生错误。 (在添加数据库之前，启动没有错误)。另外，我知道我需要创建用于更新和删除记录的方法，但希望首先创建数据库。我看了2天了，没找到问题所在。任何帮助将不胜感激。

类(class)问题:

public class Question {
    private Integer questionID;
    private String questionName;
    private String optionA;
    private String optionB;
    private String optionC;
    private String answer;
    private Integer questionLevelID;
    private Integer categoryID;
    public Question(){
        //// TODO: 11/5/2016
    }
    public Question (Integer questionID, String questionName, String optionA,
                     String optionB, String optionC, String answer, Integer questionLevelID,
                     Integer catID){
        this.questionID=questionID;
        this.questionName=questionName;
        this.optionA=optionA;
        this.optionB=optionB;
        this.optionC=optionC;
        this.answer=answer;
        this.questionLevelID=questionLevelID;
        this.categoryID = catID;

    }
    public void setqID(Integer questionId){
        this.questionID = questionId;
    }
    public void setqName(String questionName){
        this.questionName=questionName;
    }
    public void setqOptA(String optionA){
        this.optionA = optionA;
    }
    public void setqOptB(String optionB){
        this.optionB = optionB;
    }
    public void setqOptC(String optionC){
        this.optionC=optionC;
    }
    public void setqAns(String answer){
        this.answer = answer;
    }
    public void setQLevel(Integer questionLevelID){
        this.questionLevelID = questionLevelID;
    }
    public void setqcatID(Integer categoryID){
        this.categoryID= categoryID;
    }
    public int getqID(){
        return questionID;
    }
    public String getqName(){
        return questionName;
    }
    public String getqOptA(){
        return optionA;
    }
    public String getqOptB(){
        return optionB;
    }
    public String getqOptC(){
        return optionC;
    }
    public String getqAns(){
        return answer;
    }
    public Integer getqLevel(){
        return questionLevelID;
    }
    public Integer getqCatID(){
        return categoryID;
    }
}

主要 Activity :

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.CompoundButton;
import android.widget.RadioButton;
import android.util.Log;

import java.util.List;


import static android.R.attr.id;

public class EduTriviaMain extends AppCompatActivity {

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


    }

    public String onCheckedChanged(View view) {
        boolean checked = ((RadioButton) view).isChecked();
        String category = "";
        switch (view.getId()) {
            case R.id.englishRadioButton:
                if (checked) {
                    category = "english";
                    Intent intent = new Intent(this,TriviaQuestion.class);
                    startActivity(intent);
                    return category;
                }
                break;

            case R.id.historyRadioButton:
                if (checked) {
                category = "history";
                    Intent intent = new Intent(this,TriviaQuestion.class);
                    startActivity(intent);
                    return category;
                }
                break;
            case R.id.mathRadioButton:
                if (checked) {
                    category = "math";
                    Intent intent = new Intent(this,TriviaQuestion.class);
                    startActivity(intent);
                    return category;
                }
                break;
            default:

                break;

        }
        return category;
    }
}

DBHelper类:

   import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.ArrayList;
import java.util.List;

public class DBHandler extends SQLiteOpenHelper{
    //Database Version
    private static final int DATABASE_VERSION=1;
    //Database Name
    private static final String DATABASE_NAME ="eduTrivia";
    //table names

     private static final String TABLE_QUESTION="question";
    //question table column names
    private static final String KEY_QUESTIONID = "questionID";
    private static final String KEY_QUESTION="questionName";
    private static final String KEY_OPTIONA="optionA";
    private static final String KEY_OPTIONB="optionB";
    private static final String KEY_OPTIONC="optionC";
    private static final String KEY_ANSWER="answer";
    private static final String KEY_LEVEL = "questionLevelID";
    private static final String KEY_CATEGORYID="categoryID";

    private static final String CREATE_TABLE_QUESTION ="CREATE TABLE"
          + TABLE_QUESTION +"("
          + KEY_QUESTIONID +"INTEGER PRIMARY KEY,"
          + KEY_QUESTION + "TEXT,"
          + KEY_OPTIONA + "TEXT,"
          + KEY_OPTIONB + "TEXT,"
          + KEY_OPTIONC + "TEXT,"
          + KEY_ANSWER + "TEXT,"
          + KEY_LEVEL + "INTEGER,"
          + KEY_CATEGORYID + "INTEGER"+")";

          @Override
    public void onCreate(SQLiteDatabase db) {
           db.execSQL(CREATE_TABLE_QUESTION);
        addQuestions();
        }

        private void addQuestions(){
        Question q1 = new Question(1,"How do you write this number using words? 752",
                "five hudnred sixty-two","seven hundred sixty-two", "seven hundred fifty-two",
                "C",1,1);
        Question q2 = new Question(2,"Round 5,764,438 to the nearest hundred thousand",
                "6,200,000","5,800,000","5,700,000","B",1,1);
        Question q3= new Question(3,"Which equation shows the associative property of addition",
                "5+4=3+6","7+(4+3)=(7+4)+3", "0+8=8","B",1,1);
        Question q4 = new Question(4,"Select the adjective in this sentence: Nina is a strong worker",
                "Nina","strong","worker","B",1,2);
        Question q5 = new Question (5,"Select the adjective in this sentence: The twon has three banks",
                "The","town","three","C",1,2);
            }

            @Override
   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("drop table if exists"+TABLE_QUESTION);
     onCreate(db);
     }
      //constructor and getInstance() method
    private static DBHandler mDBHANDLER;
        public static synchronized DBHandler getInstance(Context context) {
            if (mDBHANDLER==null){
                mDBHANDLER=new DBHandler(context.getApplicationContext());
            }
            return mDBHANDLER;
        }
    public DBHandler(Context context){
        super(context, DATABASE_NAME,null,DATABASE_VERSION);
    }
      public void addQuestion(Question question){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_QUESTIONID,question.getqID());
        values.put(KEY_QUESTION,question.getqName());
        values.put(KEY_OPTIONA,question.getqOptA());
        values.put(KEY_OPTIONB,question.getqOptB());
        values.put(KEY_OPTIONC,question.getqOptC());
        values.put(KEY_ANSWER,question.getqAns());
        values.put(KEY_LEVEL,question.getqLevel());
        values.put(KEY_CATEGORYID,question.getqCatID());
        db.insert(TABLE_QUESTION,null,values);
        db.close();
    }
            //reading records

            public Question getQuestion(int id){
        SQLiteDatabase db=this.getReadableDatabase();
        Cursor cursor = db.query(TABLE_QUESTION, new String[]{
            KEY_QUESTIONID, KEY_QUESTION
        },KEY_QUESTIONID + "=?",
        new String[]{
                String.valueOf(id)},null,null,null,null);
        if (cursor !=null)
            cursor.moveToFirst();
        Question question = new Question(Integer.parseInt(cursor.getString(0)),
                cursor.getString(1),cursor.getString(2), cursor.getString(3),
                cursor.getString(4),cursor.getString(5),Integer.parseInt(cursor.getString(6)),
                Integer.parseInt(cursor.getString(7)));

        return question;
    }
     public List<Question> getAllQuestions(){
        //Select all questions query
        List questionList = new ArrayList<Question>();
        String selectAll = "SELECT * FROM "+TABLE_QUESTION;
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectAll,null);
        //loop through all rows and add to the list
        if (cursor.moveToFirst()){
            do{
                Question question = new Question ();
                question.setqID(Integer.parseInt(cursor.getString(0)));
                question.setqName(cursor.getString(1));
                question.setqOptA(cursor.getString(2));
                question.setqOptB(cursor.getString(3));
                question.setqOptC(cursor.getString(4));
                question.setqAns(cursor.getString(5));
                //adding to list
                questionList.add(question);
            }while (cursor.moveToNext());
        }
        return questionList;
    }
    }

琐事问题 Activity :

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;

import java.util.List;

import static android.R.id.list;

public class TriviaQuestion extends AppCompatActivity {
    List<Question> questionList;
    int score=0;
    int questionID = 0;
    Question currentQ;
    TextView txtQuestion;
    RadioButton rda,rdb,rdc;
    Button next;

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

        DBHandler db = new DBHandler(this);
        questionList = db.getAllQuestions();
        currentQ = questionList.get(questionID);
        txtQuestion=(TextView)findViewById(R.id.textView1);
        rda=(RadioButton)findViewById(R.id.radio0);
        rdb=(RadioButton)findViewById(R.id.radio1);
        rdc=(RadioButton)findViewById(R.id.radio2);
        setQuestionView();

      }
      private void setQuestionView() {
    txtQuestion.setText(currentQ.getqName());
    rda.setText(currentQ.getqOptA());
    rdb.setText(currentQ.getqOptB());
    rdc.setText(currentQ.getqOptC());

    next.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            RadioGroup grp = (RadioGroup) findViewById(R.id.radioGroup1);
            RadioButton answer = (RadioButton) findViewById(grp.getCheckedRadioButtonId());
            if (currentQ.getqAns().equals(answer.getText())) {
                score++;
            }
            currentQ = questionList.get(questionID);
            setQuestionView();
        }
     });
    }

}

琐事问题布局 XML

  <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_trivia_question"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.rasmussenandroid.sandra.edutrivia.TriviaQuestion">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:orientation="vertical" >
    <TextView
        android:id="@+id/textView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Large Text"
        android:textAppearance="?android:attr/textAppearanceLarge" />
    <RadioGroup
        android:id="@+id/radioGroup1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.04" >
        <RadioButton
            android:id="@+id/radio0"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="RadioButton" />
        <RadioButton
            android:id="@+id/radio1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="RadioButton" />
        <RadioButton
            android:id="@+id/radio2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="RadioButton" />
    </RadioGroup>
    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="next" />
</LinearLayout>

</RelativeLayout>

Answer 1

该错误告诉您问题所在 - SQL 查询构造不正确。各个术语之间应该有空格 - 例如，CREATE TABLE 问题应该是 CREATE TABLE 问题。

尝试使用以下行创建 CREATE_TABLE_QUESTION :

private static final String CREATE_TABLE_QUESTION ="CREATE TABLE "
      + TABLE_QUESTION +" ( "
      + KEY_QUESTIONID +" INTEGER PRIMARY KEY, "
      + KEY_QUESTION + " TEXT , "
      + KEY_OPTIONA + " TEXT, "
      + KEY_OPTIONB + " TEXT, "
      + KEY_OPTIONC + " TEXT, "
      + KEY_ANSWER + " TEXT, "
      + KEY_LEVEL + " INTEGER, "
      + KEY_CATEGORYID + " INTEGER "+")";