Hello Mehrdad ilchizadeh,
So to load the dataset instead of the old code :
var dataSet = connection.ExecuteQuery(dataClassInfo.ClassName + ".selectall", null, whereCondition);
You now change it in Kentico 8.2 to :
// Loads the form's data
ObjectQuery<BizFormItem> dataSet = BizFormItemProvider.GetItems(className)
The new technology in Kentico 8.2 is also used in the document queries, to known more about this it is nice to read this article from Martin Hejtmanek : Kentico 8 Technology - Introduction to DataQuery.
Good luck with programming in Kentico!
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