我试图在数据库中存储一些评论然后检索它们并在textview中显示它们但是当我尝试访问我的数据库时，通过游标得到0的计数。我没有错误，应用程序工作正常。
这是从数据库添加和检索数据的代码
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "ReviewManager ";
private static final String TABLE_REVIEWS = "Review";
private static final String KEY_ID = "reference";
private static final String KEY_NAME = "review";
public DatabaseHandler(Context context) {
super(context, null, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
String CREATE_REVIEW_TABLE="CREATE TABLE " + TABLE_REVIEWS +"(" + KEY_ID + " TEXT," + KEY_NAME +" TEXT" + ")";
db.execSQL(CREATE_REVIEW_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldversion, int newversion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + TABLE_REVIEWS);
onCreate(db);
}
// Adding new contact
public void addReview(Reviews r) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_ID, r.getReference());
values.put(KEY_NAME, r.getReview());
db.insert(TABLE_REVIEWS, null, values);
db.close();
}
public List<Reviews> getAllReviews(String reference) {
SQLiteDatabase db = this.getWritableDatabase();
List<Reviews> reviewList = new ArrayList<Reviews>();
String selectQuery = "SELECT * FROM " + TABLE_REVIEWS + " WHERE " + KEY_ID + "='" + reference+"'";
Cursor cursor = db.rawQuery(selectQuery, null);
if(cursor.getCount()!=0)
{
if (cursor.moveToFirst()) {
do {
Reviews review = new Reviews();
review.setReference(cursor.getString(0));
review.setReview(cursor.getString(1));
// Adding contact to list
reviewList.add(review);
} while (cursor.moveToNext());
}
}
else {
Log.d("no data", "no data");
}
cursor.close();
return reviewList;
}
}
这是我主要活动中的代码，我尝试显示数据..
final TextView tv = (TextView) findViewById(R.id.review);
Log.d("Reading: ", "Reading all contacts..");
List<Reviews> reviews = db.getAllReviews(reference);
for (Reviews r : reviews)
{
tv.append(r.getReview()+"\n");
}
final EditText et = (EditText) findViewById(R.id.typereview);
Button b = (Button) findViewById(R.id.addreview);
b.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String review = et.getText().toString();
Log.d("Insert: ", "Inserting ..");
db.addReview(new Reviews(reference,review));
tv.append(review+ "\n");
}
});