Question

I’m having some difficulty understanding the update command for SQLite.

In my example I am perform an update database, but if there’s an error I’m delivering an error message. If the user trys to update a record that doesn’t exist, I’m not getting an error message.

Here is my code, first the update command, and then my call:

public long updateContact(String firstName, String lastName, String address, String city, String state, 
         int zipCode, long mobileNumber, long altNumber, String email) {
    ContentValues contactInfo = new ContentValues();
    contactInfo.put(KEY_FNAME, firstName);
    contactInfo.put(KEY_LNAME, lastName);
    contactInfo.put(KEY_ADDR, address);
    contactInfo.put(KEY_CITY, city);
    contactInfo.put(KEY_STATE, state);
    contactInfo.put(KEY_ZIP, zipCode);
    contactInfo.put(KEY_MOBILE, mobileNumber);
    contactInfo.put(KEY_ALT, altNumber);
    contactInfo.put(KEY_EMAIL, email);

    String where = "FIRSTNAME = '" + firstName + "' AND LASTNAME = '" + lastName + "'";

    return db.update(DATABASE_TABLE, contactInfo, where, null);
}

The call:

if (searchTerm.length() > 0) {
                        id = db.updateContact(fName, lName, address.getText().toString().trim(), 
                                    city.getText().toString().trim(), state.getSelectedItem().toString().trim(), Integer.parseInt(zip.getText().toString().trim()), 
                                    Long.valueOf(mobile.getText().toString().trim()), Long.valueOf(alternate.getText().toString().trim()), 
                                    email.getText().toString().trim());
                        if (id == -1) {
                            DisplayErrorDialog("I'm sorry, we can not update the contact with the present data.");
                        }
                    }

The update is working when I give it valid data. But when I give it invalid data (name that isn’t in the database), I’m not getting the appropriate error message.

Answer 1

The return value is the number of rows updated, not the id. Check for 0, not -1. This implies you could be updating more than one record, which is how database updates work generally.