How to create a Combo box in a Tablview Model

[ChrisW67]

Yes true but in that example everything is handled by QSqlTableModel class which automatically detects the queries and place the combo box where it is necessary , which is invalid in my case. My model

The example you linked to has nothing to do with an SQL model. The model data can come from anywhere as long as it is presented using the QAbstractItemModel interface. The model provides data only.

The rendering of data in a view has nothing to do with the model. The view passes the painting and editor creation for each cell to a delegate, either the default one or one you provide, and the delegate decides what to display for the data the model is providing. The model may provide data indicating a colour, font, icon etc. but the view delegate can choose how to use (or ignore) that information when displaying the data. The type of editor provided for a cell is entirely decided by the delegate.