#XOJO RECORD HOW TO#
If the sequence number doesn't exist, the record was deleted before I refreshed my listbox. custom slider in Xojo - YouTube How to create a custom slider or a custom trackbar in Xojo.custom slider in xojo. If true, the record still exits and I use a server side cursor to lock the record while I perform whatever operation needs to happen. There are no plugins, dynamic link libraries (dll), COM, or Active X parts to add. The book is written as a guide and reference to Xojo programmers who program Desktop Applications in Windows and Mac. The Xojo rowtag can also take an array if you want to get creative and put both the RecID and the sequence # in the rowtag.īefore I complete any record operations, i check the DB to see if the sequence # still exists and if so, does the RecID match. Program SQLite with Xojo API2 delves into the mystery of programming a back-end database. Which one goes where is up to you and your programming style. I retrieve both RecID and sequence number from the DB when populating a listbox and place one field in the rowtag and one in a column with a width of 0 making it invisible. I also set this field's "Unique" attribute to true. I found it safer to place a ULLONG field in tables were I needed permanency and use either a Serial32 or Serial64 (which is basically a sequence) to generate a unique identifier for each record.
If another user deletes, let's say record 5 (RecID 5), and you click on the listbox with the rowtag of (RecID) 5 - any DB operations you perform with that RecID will be on the wrong data. A RecID can be reused when a record is deleted and new data is inserted into the DB.įor example, after you populate the listbox with the records you want (using the RecID as the rowtag), this data now becomes stale. Did you know that Xojo can write binary files Yup, it can In this tutorial, we'll explore how to write such records using the BinarySteam. I quickly had issues with data consistency because the RecID field is not a permanent identifier for data. I also used the RecID field as the rowtag in a Xojo listbox.
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