Check if cursor has results

I am using a database to store date and want a single column returned based on which id is given in the where claus. ``` public String getPmax(String serial) { String[] columns = new String[]{KEY_SERIAL, KEY_PMAX}; Cursor c = ourDatabase.query(DATABASE_TABLE, columns, "serial = " + serial, null, null, null, null); String result = "nothing found"; if(c != null) { int iPmax = c.getColumnIndex(KEY_PMAX); c.moveToFirst(); result = c.getString(iPmax); } return result; } ``` This code works if I use a serial that is in the database but it gives me a force close when i am using a serial that's not in the database! it says: ``` 04-11 16:31:19.423: E/AndroidRuntime(21226): java.lang.RuntimeException: Unable to start activity ComponentInfo{nl.janjanus.solardetect/nl.janjanus.solardetect.DatabaseView}: android.database.sqlite.SQLiteException: no such column: g: , while compiling: SELECT serial, pmax FROM SolareCel WHERE serial = g ``` So my question is: How do I check if there is result? or do I need to check if the serial given is a serial that is in the database?