Can't write data into SQLite database Android Studio (Java)

Question

I'm trying to save data into a sqlite db, i have looked around but the strucutre for the helper is always this, i can't find out what's the problem. I don't get any exception, just is impossible write data into the db

public class DBhelper extends SQLiteOpenHelper {
    private static final String QR_TABLE = "QR_TABLE";
    private static final String ID = "COLUMN_ID";
    private static final String C_TEXT = "COLUMN_TEXT";
    private static final String C_DATE = "COLUMN_DATE";
    private static final String DB_NAME = "qreader.db";

    public DBhelper(Context context) {
        super(context, DB_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String createTableStatement = "CREATE TABLE " + QR_TABLE + " (" + ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + C_TEXT + " TEXT, "+ C_DATE + "TEXT)";
        db.execSQL(createTableStatement);
    }

 
    public boolean addRow(String text, String date){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues cv = new ContentValues();

        cv.put(C_TEXT, text);
        cv.put(C_DATE, date);

        long result = db.insert(QR_TABLE, null, cv);
        db.close();
        if(result == -1){
            return false;
        }
        return true;

    }

Here is the MainActivity file

public class MainActivity extends AppCompatActivity {

    protected static TextView tvresult;
    private DBhelper db;
...

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toast.makeText(this, "NOT DELETED", Toast.LENGTH_SHORT).show();
        db = new DBhelper(this);
        Boolean res;
        for(int i=0; i<30; i++){
            res = db.addRow("Prova", "10");
            if(res)
                Log.w("myapp", "Added");
        }
        Log.w("App", db.getValues().toString());
...

On my log i see that the result from the getValues() is empty, so the database is not filled, and the "Added" message is never sent to the logcat.

Post the code of getValues(). – forpas Jun 11 '21 at 18:40 — forpas, Jun 11 '21 at 18:40

Dharmender Manral · Answer 1 · 2021-06-12T07:25:16.517

0

Try below query with reinstall your app

String createTableStatement = "CREATE TABLE " + QR_TABLE + "(" + ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + C_TEXT + " TEXT, " + C_DATE + " TEXT" +")";

edited Jun 12 '21 at 07:25

answered Jun 12 '21 at 03:32

Dharmender Manral

1,504
1
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What do you mean after unistall the app? The database is created by a class in the app, it must be installed and launched to work – Alberto Bertoncini Jun 12 '21 at 07:24
just reinstall your app – Dharmender Manral Jun 12 '21 at 07:25
Already tried, even in another new device – Alberto Bertoncini Jun 12 '21 at 07:48

score 0 · Accepted Answer · answered Jun 12 '21 at 12:38

0

Use insertOrThrow() instead of insert() to get a helpful exception message.

It likely says that COLUMN_DATE does not exist, and the reason for that is a missing space in onCreate(): C_DATE + "TEXT)" should be C_DATE + " TEXT)". After adding the space you can uninstall your app to recreate the database file with the updated schema.

answered Jun 12 '21 at 12:38

laalto

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It was that! Really thanks, I modified the onUpgrade and create a new version to modify the schema. – Alberto Bertoncini Jun 13 '21 at 08:58

Can't write data into SQLite database Android Studio (Java)

2 Answers2