Android SQLite 不会向数据库添加值

Question

我只是想弄清楚如何使用 android SQLite，我已经学习了许多不同的教程。但出于某种原因，我无法得到任何工作。这是我使用的代码:

数据库处理器.java

package com.example.deathtrackkevin;

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 DbHandler extends SQLiteOpenHelper  {

    // All static variables
    //Database Version
    private static final int DATABASE_VERSION = 1;

    //Database Name
    private static final String DATABASE_NAME = "DeathTrackDB";

    //DeathTrack Table Name
    private static final String TABLE_DEATHTRACK = "DeathTrack";

    //Deathtrack Table Column Names
    private static final String COL_GAME_ID = "Game_ID";
    private static final String COL_GAME_NAME = "Game_Name";
    private static final String COL_KILLS = "kills";
    private static final String COL_DEATHS = "Deaths";
    private static final String COL_DATE = "date";
    private static final String COL_MATCH = "Match";


    public DbHandler(Context context){
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    //Creating Tables
    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_DEATHTRACK_TABLE = 
                "CREATE TABLE" + TABLE_DEATHTRACK + "("
                + COL_GAME_ID + "INTEGER PRIMARY KEY," 
                + COL_GAME_NAME + "TEXT,"
                + COL_KILLS + "TEXT," 
                + COL_DEATHS + "TEXT," 
                + COL_DATE + "TEXT,"
                + COL_MATCH + "TEXT" + ")";
        db.execSQL(CREATE_DEATHTRACK_TABLE);
    }

    //Upgrading Database
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Drop Older Table If Exists
        db.execSQL("DROP TABLE IF EXISTS" + TABLE_DEATHTRACK);
        onCreate(db);
    }

    /**
     * All CRUD(Create, Read, Update, Delete) Operations
     */

    //Adding New Deathtrack TODO Create array for deathtrack
    void addDeathtrack(DeathTrack deathtrack) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(COL_GAME_ID, deathtrack.get_game_id());
        values.put(COL_GAME_NAME, deathtrack.get_game_name());
        values.put(COL_KILLS, deathtrack.get_kills());
        values.put(COL_DEATHS, deathtrack.get_Deaths());
        values.put(COL_DATE, deathtrack.get_Date());
        values.put(COL_MATCH, deathtrack.get_match());

        //Inserting Row
        db.insert(TABLE_DEATHTRACK, null, values);
        db.close();
    }
    //TODO Getting Single Deathtrack
    DeathTrack getDeathtrack(int id){
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.query(TABLE_DEATHTRACK, new String[] {COL_GAME_ID, COL_GAME_NAME, COL_KILLS, COL_DEATHS, COL_DATE, COL_MATCH}, COL_GAME_ID + "=?", new String[] {String.valueOf(id)}, null, null, null, null);
        if(cursor != null)
            cursor.moveToFirst();

        DeathTrack deathtrack = new DeathTrack(Integer.parseInt(cursor.getString(0)), 
                cursor.getString(1), 
                cursor.getString(2), 
                cursor.getString(3), 
                cursor.getString(4), 
                cursor.getString(5));

        return deathtrack;
    }

    //TODO Get all deathtrack values    
    public List<DeathTrack> getAllDeathtrack(){
        List<DeathTrack> deathtrackList = new ArrayList<DeathTrack>();
        //Select all Query
        String selectWhere = "SELECT * FROM" + TABLE_DEATHTRACK;

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectWhere, null);

        //Looping through all rows and adding to list
        if(cursor.moveToFirst()){
            do{
                DeathTrack deathtrack = new DeathTrack();
                deathtrack.set_game_name(cursor.getString(0));
                deathtrack.set_kills(cursor.getString(1));
                deathtrack.set_Deaths(cursor.getString(2));
                deathtrack.set_Date(cursor.getString(3));
                deathtrack.set_match(cursor.getString(4));
                //Add deathtrack to list
                deathtrackList.add(deathtrack);
            } while (cursor.moveToNext());
        }
        return deathtrackList;
    }
    //TODO Delete deathtrack value by game name
    public void deleteDeathtrack(DeathTrack deathtrack){
        SQLiteDatabase db = this.getWritableDatabase(); 
        db.delete(TABLE_DEATHTRACK, COL_GAME_NAME + "= ?", new String[]{            String.valueOf(deathtrack.get_game_name())});
        db.close();
    }


}

SQLTester.java

package com.example.deathtrackkevin;

    import java.util.List;

    import android.app.Activity;
    import android.os.Bundle;
    import android.util.Log;


    public class SQLTester extends Activity {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.sqltester_layout);

            DbHandler db = new DbHandler(this);

            /**
             * CRUD Operations
             * */
            // Inserting Contacts
            Log.d("Insert: ", "Inserting .."); 
            db.addDeathtrack(new DeathTrack(1, "cod2", "4", "2", "02-02-12", "1"));        
            db.addDeathtrack(new DeathTrack(2, "cod3", "4", "2", "02-02-12", "1"));
            db.addDeathtrack(new DeathTrack(3, "cod4", "4", "2", "02-02-12", "1"));
            db.addDeathtrack(new DeathTrack(4, "cod5", "4", "2", "02-02-12", "1"));

            // Reading all contacts
            Log.d("Reading: ", "Reading all contacts.."); 
            List<DeathTrack> contacts = db.getAllDeathtrack();       

            for (DeathTrack cn : contacts) {
                String log = "Game_Id: "+cn.get_game_id()+" ,Game_Name: " + cn.get_game_name() + " ,Kills: " + cn.get_kills()+ " ,Deaths: " + cn.get_Deaths()+ " ,Date: " + cn.get_Date()+ " ,Match: " + cn.get_match();
                    // Writing Contacts to log
            Log.v("dt", "name "+log);
        }
        }
    }

问题基本上我所需要的只是有人告诉我是否有问题。我没有收到任何 logcat 错误或任何其他类型的错误，所以我无法使用它们来弄清楚发生了什么

问候乔

Answer 1

看来你的空格键坏了...

    String CREATE_DEATHTRACK_TABLE = 
            "CREATE TABLE" + TABLE_DEATHTRACK + "("
            + COL_GAME_ID + "INTEGER PRIMARY KEY," 
            + COL_GAME_NAME + "TEXT,"
            + COL_KILLS + "TEXT," 
            + COL_DEATHS + "TEXT," 
            + COL_DATE + "TEXT,"
            + COL_MATCH + "TEXT" + ")";

和

String selectWhere = "SELECT * FROM" + TABLE_DEATHTRACK;

行不通。
相反，你需要写

    String CREATE_DEATHTRACK_TABLE = 
            "CREATE TABLE " + TABLE_DEATHTRACK + " ("
            + COL_GAME_ID + " INTEGER PRIMARY KEY, " 
            + COL_GAME_NAME + " TEXT, "
            + COL_KILLS + " TEXT, " 
            + COL_DEATHS + " TEXT, " 
            + COL_DATE + " TEXT, "
            + COL_MATCH + " TEXT)";

和

String selectWhere = "SELECT * FROM " + TABLE_DEATHTRACK;

[编辑]

您正在使用保留关键字 MATCH。
您最好将其更改为 Round 或 Challenge 之类的内容。
供您引用:https://www.sqlite.org/lang_keywords.html