Question

我已经编写了下面的代码，用于在数据库中插入一组信息，但遗憾的是它已经关闭了，我不知道为什么。

我查看了logcat，并了解问题在于这个lin db = dbHelper.getWritableDatabase();

任何人都可以帮助我理解原因并解决这个问题吗？

提前致谢

mainActivity：

public class MainActivity extends Activity {

DBHelper dbHelper = null;
SQLiteDatabase db = null;
ContentValues values = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    dbHelper = new DBHelper(this, "simple_db", null, 1);

    db = dbHelper.getWritableDatabase();
    values = new ContentValues();
    values.put("name", "Barry");
    values.put("amount", "100");
    db.insert("simpletable", "", values);



}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

DBHelper：

    public class DBHelper extends SQLiteOpenHelper{
Context c;
public DBHelper(Context context, String name, SQLiteDatabase.CursorFactory factory,
        int version) {

    super(context, name, factory, version);
    // TODO Auto-generated constructor stub
}

@Override
public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub
    String creatString = "CREATE TABLE IF NOT EXISTS simpletable" + 
    "(_id INTEGER PRIMARY KEY AUTOINCREMENT, "
            + "name TEXT NOT NULL"
    + "amount INTEGER NOT NULL);";

    db.execSQL(creatString);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub
    String dropString = 
            "DROP TABLE IF EXISTS simpletable;";
    db.execSQL(dropString);
    onCreate(db);

}

}

Answer 1

将onCreate（）方法更改为：

    @Override
public void onCreate(SQLiteDatabase db) {
    String creatString = "CREATE TABLE IF NOT EXISTS simpletable" + 
            "(_id INTEGER PRIMARY KEY AUTOINCREMENT, "
            + "name TEXT NOT NULL,"
            + "amount INTEGER NOT NULL);";

    db.execSQL(creatString);
}

所有你都没事。

您的CREATE TABLE语句构造错误，第二行和第三行之间缺少逗号。

在database.getwritable中强制关闭

1 个答案: