Question

我正在创建一个Android应用程序。

当我尝试编辑添加问题或qid的值时，我正在使用sqlite。在我的android工作室里面。它没有更新。旧数据库值为5 + 2;我将所有这些都改为1. 5 + 2。

但是当我尝试在我的android工作室中编辑/修改它时，它不会更新。

什么错了？请帮帮我。

这是我的代码。

package com.example.testing;

import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class QuizHelper extends SQLiteOpenHelper {
    private static final int DATABASE_VERSION = 1;
    // Database Name
    private static final String DATABASE_NAME = "mathsone";
    // tasks table name
    private static final String TABLE_QUEST = "quest";
    // tasks Table Columns names
    private static final String KEY_ID = "qid";
    private static final String KEY_QUES = "question";
    private static final String KEY_ANSWER = "answer"; // correct option
    private static final String KEY_OPTA = "opta"; // option a
    private static final String KEY_OPTB = "optb"; // option b
    private static final String KEY_OPTC = "optc"; // option c
    private SQLiteDatabase dbase;
    public QuizHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        dbase = db;
        String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUEST + " ( "
                + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_QUES
                + " TEXT, " + KEY_ANSWER + " TEXT, " + KEY_OPTA + " TEXT, "
                + KEY_OPTB + " TEXT, " + KEY_OPTC + " TEXT)";
        db.execSQL(sql);
        addQuestion();

        // db.close();
    }
    private void addQuestion() {
        Question q1 = new Question("1. 5+2 = ?", "7", "8", "6", "7");
        this.addQuestion(q1);
        Question q2 = new Question("2. 2+18 = ?", "18", "19", "20", "20");
        this.addQuestion(q2);
        Question q3 = new Question("3. 10-3 = ?", "6", "7", "8", "7");
        this.addQuestion(q3);
        Question q4 = new Question("4. 5+7 = ?", "12", "13", "14", "12");
        this.addQuestion(q4);
        Question q5 = new Question("5. 3-1 = ?", "1", "3", "2", "2");
        this.addQuestion(q5);
        Question q6 = new Question("6. 0+1 = ?", "1", "0", "10", "1");
        this.addQuestion(q6);
        Question q7 = new Question("7. 9-9 = ?", "0", "9", "1", "0");
        this.addQuestion(q7);
        Question q8 = new Question("8. 3+6 = ?", "8", "7", "9", "9");
        this.addQuestion(q8);
        Question q9 = new Question("9. 1+5 = ?", "6", "7", "5", "6");
        this.addQuestion(q9);
        Question q10 = new Question("10. 7-5 = ?", "3", "2", "6", "2");
        this.addQuestion(q10);
        Question q11 = new Question("11. 7-2 = ?", "7", "6", "5", "5");
        this.addQuestion(q11);
        Question q12 = new Question("12. 3+5 = ?", "8", "7", "5", "8");
        this.addQuestion(q12);
        Question q13 = new Question("13. 0+6 = ?", "7", "6", "5", "6");
        this.addQuestion(q13);
        Question q14 = new Question("14. 12-10 = ?", "1", "2", "3", "2");
        this.addQuestion(q14);
        Question q15 = new Question("15. 12+2 = ?", "14", "15", "16", "14");
        this.addQuestion(q15);
        Question q16 = new Question("16. 2-1 = ?", "2", "1", "0", "1");
        this.addQuestion(q16);
        Question q17 = new Question("17. 6-6 = ?", "6", "12", "0", "0");
        this.addQuestion(q17);
        Question q18 = new Question("18. 5-1 = q?", "4", "3", "2", "4");
        this.addQuestion(q18);
        Question q19 = new Question("19. 4+2 = 19?", "6", "7", "5", "6");
        this.addQuestion(q19);
        Question q20 = new Question("20. 5+1 = ?", "6", "7", "5", "6");
        this.addQuestion(q20);
        Question q21 = new Question("5-4 = ?", "5", "4", "1", "1");
        this.addQuestion(q21);
        // END
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
        // Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUEST);
        // Create tables again
        onCreate(db);
    }
    // Adding new question
    public void addQuestion(Question quest) {
        // SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_QUES, quest.getQUESTION());
        values.put(KEY_ANSWER, quest.getANSWER());
        values.put(KEY_OPTA, quest.getOPTA());
        values.put(KEY_OPTB, quest.getOPTB());
        values.put(KEY_OPTC, quest.getOPTC());
        // Inserting Row
        dbase.insert(TABLE_QUEST, null, values);
    }
    public ArrayList<Question> getAllQuestions() {
        ArrayList<Question> quesList = new ArrayList<Question>();

        // Select All Query
        String selectQuery = "SELECT  * FROM " + TABLE_QUEST;
        dbase = this.getReadableDatabase();
        Cursor cursor = dbase.rawQuery(selectQuery, null);
        // looping through all rows and adding to list


        if (cursor.moveToFirst()) {
            do {
                Question quest = new Question();
                quest.setID(cursor.getInt(0));
                quest.setQUESTION(cursor.getString(1));
                quest.setANSWER(cursor.getString(2));
                quest.setOPTA(cursor.getString(3));
                quest.setOPTB(cursor.getString(4));
                quest.setOPTC(cursor.getString(5));
                quesList.add(quest);

            } while (cursor.moveToNext());
        }
        // return quest list
        return quesList;
    }
}

Answer 1

要使用SQLite更新记录，请使用此 -

首先制作一个ContentValues对象：

AndroidOpenDbHelper openDbHelperObj = new AndroidOpenDbHelper(this);
SQLiteDatabase sqLiteDatabase = openDbHelperObj.getWritableDatabase();
ContentValues contentValues = new ContentValues();

 contentValues.put(AndroidOpenDbHelper.COLUMN_NAME_ORIGIN,Origin);
 contentValues.put(AndroidOpenDbHelper.COLUMN_NAME_DESTINATION,Destination);

然后使用更新方法，现在应该可以使用：

long affectedRowId = sqLiteDatabase.update(AndroidOpenDbHelper.TABLE_NAME_TEST, contentValues, "_id="+id, null);

希望这会有所帮助!!

Answer 2

更改版本的值

private static final int DATABASE_VERSION = 3;

并且会更新

Sqlite数据库无法更新

2 个答案: