CODEWITHSUNDEEP
javaandroidsqlite
Damian Ziółkowski
Damian Ziółkowski

Reputation: 87

Cursor is empty but query is (supposedly) right

I've got very strange problem. My snippet is looking like that

public Wynik getData(int pomiar, int godzina) {
    Wynik wynik = null;
    String query = "SELECT * FROM " + "insulina" + " WHERE godzina = " + godzina +
            " AND cukier = " + pomiar;
    SQLiteDatabase db = this.getReadableDatabase();
    try (Cursor cursor = db.rawQuery(query, null)) {
        Log.i("tag", "cursor length:" + cursor.getCount());
        if (cursor.getCount() > 0) {
            String s = DatabaseUtils.dumpCursorToString(cursor);
            Log.d("s", s);
            cursor.moveToFirst();
            wynik = new Wynik
                    (cursor.getInt(cursor.getColumnIndexOrThrow("godzina")),
                            cursor.getString(cursor.getColumnIndexOrThrow("insulina")),
                            cursor.getInt(cursor.getColumnIndexOrThrow("dawka")),
                            cursor.getString(cursor.getColumnIndexOrThrow("cialo")));
        }

        cursor.close();
        return wynik;

(sorry for not English convention, but it was meant to be quick, routinely project)

Whole app idea is to help my friend with his grandmother's diabetes. He would insert an result of blood sugar level test (cukier) and time of test is checked automatically (godzina). Based on those, app should return a whole result (wynik), with required dose of insulin (dawka), type of it (insulina) and part of body from which the blood should be taken (cialo).

Database looks like this: enter image description here

So for example. The blood result is 10 (it's only thing which user is inserting) and it's 7 P.M (19, by 24-hours convention - the program is giving the closest hour of test, so it's 18). So, the query looks like

SELECT * FROM insulina WHERE godzina = 18 AND cukier = 10

And here's my problem. The app is recognizing cursor length as 0 (it should be 1) even if my other app related to database creation (DB Browser for SQLite) is giving out my result properly with the same query enter image description here

Also Android Studio says that database is sucessfully opened.

I cannot find a fault here. And I'm really confused with this problem.

Upvotes: 0

Views: 73

Answers (1)

Mark
Mark

Reputation: 9919

I think the query should be :

String query = "SELECT * FROM insulina WHERE godzina = ? AND cukier = ?";
SQLiteDatabase db = this.getReadableDatabase();
try (Cursor cursor = db.rawQuery(query, new String[]{String.valueOf(godzina), String.valueOf(pomiar)})) { 
//... rest of code

Also looks like you're using "try with resources" so the close isn't explicitly necessary.

Upvotes: 1

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