使用数据库时应用程序崩溃答案

【问题标题】：App crashes when using Database使用数据库时应用程序崩溃
【发布时间】：2016-03-26 20:04:18
【问题描述】：

我正在创建一个用作课程作业的应用程序。我对 Android 开发和使用 SQLite 仍然很陌生。该应用程序的想法是允许用户插入他们正在观看或阅读的系列的详细信息，例如标题、观看/播放的剧集、季节等。

在我开始使用 SQLite 之前一切都很好。该应用程序在两个不同的点崩溃，第一个是在 home 类的列表视图上，第二个是当按下调用“insert_tv”类的按钮时。

DatabaseHandler 与 createTable、insert 和 cursor 方法。

public class DatabaseHandler extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;

private static final String DATABASE_NAME = "SeriesTracker";

private static final String TABLE_TV = "tv";
private static final String COLUMN_KEY ="ID";
private static final String COLUMN_TITLE = "title";
private static final String COLUMN_EPISODES_WATCHED = "episodes_watched";
private static final String COLUMN_EPISODES_AIRED = "episodes_aired";
private static final String COLUMN_SEASONS_WATCHED = "seasons_watched";
private static final String COLUMN_SEASONS_AIRED = "season_aired";
private static final String COLUMN_RATING = "rating";
private static final String COLUMN_DESCRIPTION = "description";

public DatabaseHandler(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
 public void onCreate(SQLiteDatabase db){
     String CREATE_tv_TABLE = "CREATE TABLE " + TABLE_TV +"("
             + COLUMN_KEY + "INTEGER AUTOINCREMENT" + COLUMN_TITLE + " VARCHAR PRIMARY KEY, " + COLUMN_EPISODES_WATCHED +
             " TINYINT," + COLUMN_EPISODES_AIRED + " TINYINT," + COLUMN_SEASONS_WATCHED + " TINYINT,"
             + COLUMN_SEASONS_AIRED + " TINYINT," + COLUMN_RATING + " TINYINT," + COLUMN_DESCRIPTION
             + " VARCHAR," + ")";
     db.execSQL(CREATE_tv_TABLE);
 }
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    db.execSQL("DROP TABLE IF EXISTS " + TABLE_TV);

    onCreate(db);

}

public boolean insertTv(String title, int episodes_watched, int episodes_aired, int seasons_watched, int seasons_aired, int rating, String description){
    SQLiteDatabase db = getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(COLUMN_TITLE, title );
    contentValues.put(COLUMN_EPISODES_WATCHED, episodes_watched );
    contentValues.put(COLUMN_EPISODES_AIRED, episodes_aired);
    contentValues.put(COLUMN_SEASONS_WATCHED, seasons_watched );
    contentValues.put(COLUMN_SEASONS_AIRED, seasons_aired);
    contentValues.put(COLUMN_RATING, rating);
    contentValues.put(COLUMN_DESCRIPTION, description);
    db.insert(TABLE_TV, null, contentValues);
    return true;
}

public Cursor getTv() {
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor res = db.rawQuery("SELECT * FROM TABLE_TV", null );
    return res;
}

第一次崩溃

public class Home extends ListActivity {

DatabaseHandler dbHelper;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    dbHelper = new DatabaseHandler(this);
    String[] type={"TV", "Film", "Book"};//declares the array list for each of the sections
    setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, type));

}

protected void onListItemClick(ListView i, View v, int position, long id){
    switch(position){
        case 0: //statement which is executed on the first list item
            startActivity(new Intent(Home.this, tv.class));
            DatabaseHandler result = new DatabaseHandler(getApplicationContext());
            result.getTv();
            break;
        case 1:
            startActivity(new Intent(Home.this, film.class));
            break;
        case 2:
            startActivity(new Intent(Home.this, book.class));
            break;
        default:
    }
}

第二次崩溃

public class tv extends Activity {

DatabaseHandler dbHelper;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_tv);
    dbHelper = new DatabaseHandler(this);
    Button b = (Button) findViewById(R.id.add_tv);
    b.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            startActivity(new Intent(tv.this, insert_tv.class));
        }
    });
}

通过按钮调用的类

public class insert_tv extends Activity {

DatabaseHandler dbHelper;

final EditText input1 = (EditText) findViewById(R.id.titletxt);
final String title = input1.getText().toString();

final EditText input2 = (EditText) findViewById(R.id.epswatched);
final String episodes_watched1 = input2.getText().toString();
int episodes_watched = Integer.parseInt(episodes_watched1);

final EditText input3 = (EditText) findViewById(R.id.eps_aired);
final String episodes_aired1 = input3.getText().toString();
int episodes_aired = Integer.parseInt(episodes_aired1);

final EditText input4 = (EditText) findViewById(R.id.seasons_watched);
final String seasons_watched1 = input4.getText().toString();
int seasons_watched = Integer.parseInt(seasons_watched1);

final EditText input5 = (EditText) findViewById(R.id.seasons_aired);
final String seasons_aired1 = input5.getText().toString();
int seasons_aired = Integer.parseInt(seasons_aired1);

final EditText input6 = (EditText) findViewById(R.id.ratetxt);
final String rating1 = input6.getText().toString();
int rating = Integer.parseInt(rating1);

final EditText input7 = (EditText) findViewById(R.id.destxt);
final String description = input7.getText().toString();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_insert_tv);
    dbHelper = new DatabaseHandler(this);
    Button b=(Button)findViewById(R.id.btnsave_tv);
    b.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            DatabaseHandler values = new DatabaseHandler(getApplicationContext());
            values.insertTv(title, episodes_watched, episodes_aired, seasons_watched, seasons_aired, rating, description);
        }
    });
}

}

任何解决问题的帮助将不胜感激

EDIT 这里是第一次崩溃的 logcat，当第一个 switch case“TV”被按下时发生。

03-25 19:27:01.484 6356-6356/ljmu.ac.uk.seriestracker E/AndroidRuntime: FATAL EXCEPTION: main    
    Process: ljmu.ac.uk.seriestracker, PID: 6356
    android.database.sqlite.SQLiteException: near ")": syntax error (code 1): , while compiling: CREATE TABLE tv(IDINTEGER AUTOINCREMENTtitle VARCHAR PRIMARY KEY, episodes_watched INT,episodes_aired INT,seasons_watched INT,season_aired INT,rating INT,description VARCHAR,)
    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:1676)
    at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1607)
    at ljmu.ac.uk.seriestracker.DatabaseHandler.onCreate(DatabaseHandler.java:37)
    at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:251)
    at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:187)
    at ljmu.ac.uk.seriestracker.DatabaseHandler.getTv(DatabaseHandler.java:62)
    at ljmu.ac.uk.seriestracker.Home.onListItemClick(Home.java:35)
    at android.app.ListActivity$2.onItemClick(ListActivity.java:319)
    at android.widget.AdapterView.performItemClick(AdapterView.java:300)
    at android.widget.AbsListView.performItemClick(AbsListView.java:1143)
    at android.widget.AbsListView$PerformClick.run(AbsListView.java:3044)
    at android.widget.AbsListView$3.run(AbsListView.java:3860)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5255)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:652)

【问题讨论】：

如果您遇到崩溃请发布堆栈跟踪
有什么问题。 不起作用不足以解决它。发布您的 logcat 并标记您的代码中发生异常的行。
请跟踪堆栈。

标签： android sqlite

【解决方案1】：

android.database.sqlite.SQLiteException: near ")": syntax error (code 1): , while compiling: CREATE TABLE tv(IDINTEGER AUTOINCREMENTtitle VARCHAR PRIMARY KEY, episodes_watched INT,episodes_aired INT,seasons_watched INT,season_aired INT,rating INT,description VARCHAR,)

SQL 中的语法问题：

删除最后一列和关闭)之间的,。
IDINTEGER 应该是 ID INTEGER。
AUTOINCREMENT 需要 INTEGER PRIMARY KEY，例如ID INTEGER PRIMARY KEY AUTOINCREMENT。您只能拥有一个 PRIMARY KEY 列，因此请从另一列中删除 PRIMARY KEY。
AUTOINCREMENTtitle 你需要一个逗号。

【讨论】：

【解决方案2】：

public class insert_tv extends Activity {
    final EditText input1 = (EditText) findViewById(R.id.titletxt);
    final String title = input1.getText().toString();

这是初始化变量的错误方式

试试下面的一个

public class insert_tv extends Activity {
    final EditText input1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_insert_tv);
        input1 = (EditText) findViewById(R.id.titletxt);
        ..
        Button b=(Button)findViewById(R.id.btnsave_tv);
        b.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                String title = = input1.getText().toString();
                // likewise get all text from EditText and
                // then pass it to database values
                DatabaseHandler values = new
                        DatabaseHandler(getApplicationContext());
                values.insertTv(title, episodes_watched, episodes_aired,
                    seasons_watched, seasons_aired, rating, description);
            }
        });
    }

为所有EditText 执行此操作。

希望对你有帮助

【讨论】：