Check if Record Exists in database

Question

I am trying to check if a record exists after selecting it using a query. I have one record in the table which is 'Administrator' 'abc123' and I am trying to use the following code below:

 //Define our database variables that we will use to get our data. dbhelper = new DBHelper(this); SQLiteDatabase db = dbhelper.getReadableDatabase(); //Define our select query here, check if username and password exists. String selectQuery = "SELECT * FROM " + dbTables.userTABLE + " WHERE " + dbTables.username + " = " + "'" + input_name + "'" + " AND " + dbTables.userpassword + " = " + "'" + input_password + "'"; Cursor c = db.rawQuery(selectQuery, null); //If the raw query was successfull. if(c.moveToFirst()){ Integer userID = c.getInt(0); String userName = c.getString(1); String userPassword = c.getString(2); boolean exists = (c.getCount() > 0); if( exists ) { Log.d("Database", userID.toString()); Log.d("Database", userName.toString()); Log.d("Database", userPassword.toString()); } else { Log.d("Database NO", "NO"); } } c.close(); db.close();

This works when the record exists however when the record doesn't exist it doesn't print anything at all. I have tried entering a different username and password that doesn't exist in the database and it doesn't seem to print anything. What am I doing wrong?

One don't select *. It will move all columns to the buffer. select only one column. 2nd don't invent your own security. Ping a service to authenticate. — danny117
– danny117, Commented Apr 3, 2017 at 14:18
This doesn't relate to your question, but use prepared statements! Your code is susceptible to SQL-injection attacks. — RichN
– RichN, Commented Apr 3, 2017 at 20:41

azizbekian · Accepted Answer · 2017-04-03 14:14:27Z

From docs:

Return boolean, indicating whether the move succeeded.

if (c.moveToFirst()) { ... } else { // cursor is empty, print here }

Obviously, if there are no records then move hasn't succeeded, you have to check it in else block.

Collectives™ on Stack Overflow

Check if Record Exists in database

1 Answer 1

Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Related