[Interest] Working with Q*Models and SQLite3 limitations

Jason H scorp1us at yahoo.com
Wed Feb 26 17:14:48 CET 2014

I'm trying to work with SQLite 3 and QSqlQueryModel/QSqlTableModel. Normally I have not problem using these as data sets are small, and I'm interesting in the rows in returned order.

I recently tried to grab arbitrary data from the model sample model index would be (1000,0) - (1100,C) (first C columns of row 1000 to tor 11000) and ran into some snags.
int C = colMax != -1 ? colMax : colMax= columnCount();
int R = rowMax != -1 ? rowMax : rowMax= rowCount();

Pseducode runs after setQuery(sql):
for (int row = rowMin; row< rowMax; row++) {
for (int col = colMin; row< colMax; col++) {

Qstring d = model.data(row,col).toString();

However BOTH rowCount() and columnCount() return 0. 

The only thing I can think of is to come up with a COUNT() query, but this requires me to write and maintain an additional query. The alternative, which I grimaced at, is to run through the query to get the count, then possibly iterate/reset backwards  I have not yet even seen what happens when I request model.data(1000,0); Insight on how SQLite/Qt will behave for a not-yet-loaded row is appreciated.

I'm looking for more elegant solutions than what I can come up with, or a recommendation of approach.

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