How to increment field in sqlite android database

Question

I want to increment a column in a sqlite android database. Im doing like this:

public void atualiza(String word){
   this.db.rawQuery("UPDATE words SET count = count + 1 WHERE word= ? ", new String[] {word});     
}

And I call this method on another class like this:

this.dh.atualiza(word);

But when i pull the database from the emulator and check with the SQLite Database Browser, the field is not incremented. Why?

how about if you do a select from within your code (select count from words where word=?), does it return the correct value? (are you definitely pulling the right database?) — Mathias Conradt, Aug 22 '10 at 05:45
I think `rawQuery` returns an error code. Can you check what it is? Also, updates should be made with execSQL. — MPelletier, Aug 22 '10 at 17:21

score 4 · Accepted Answer · edited May 23 '17 at 12:19

4

You should really use execSQL for a query that does not return a table: Increase the value of a record in android/sqlite database

edited May 23 '17 at 12:19

Community

answered Aug 22 '10 at 20:48

MPelletier

score 0 · Answer 2 · edited May 23 '17 at 12:07

0

edited May 23 '17 at 12:07

Community

answered Aug 22 '10 at 05:46

Konstantin Burov

I should point out that when transactions are not specified, SQLite makes its own. – MPelletier Aug 22 '10 at 17:20
Hmm.. do you know good android docs about that feature? I'd highly appreciate a link. – Konstantin Burov Aug 22 '10 at 17:22
It's a feature of SQLite, not so much as Android, but here is the official doc: http://sqlite.org/lang_transaction.html : "No changes can be made to the database except within a transaction. Any command that changes the database (basically, any SQL command other than SELECT) will automatically start a transaction if one is not already in effect. Automatically started transactions are committed when the last query finishes." – MPelletier Aug 22 '10 at 20:51
Its ok. The problem was change from rawQuery to execSQL. Thanks a lot! – rogcg Aug 22 '10 at 21:30
But how do you get the number of affected rows then? – Marcus Wolschon Sep 05 '11 at 10:52

2 Answers2