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Subject:Re: Postgresql connection
Date:Wed, 6 Feb 2019 08:08:47 -0600
From:Mark Bannister <markRemove@THISinjection-moldings.com>
Newsgroups:pnews.paradox-client_server
Thanks for all the info.  You may have answered this somewhere but, when 
you are displaying data from the Priv directory in a form, do you use 
the datamodel links or do you do that manually?

On 2/4/2019 7:46 PM, Tom Krieg wrote:
> You need to change the way you think when you use any SQL database.
> 
> First, I would use sequences and an integer field for keys, rather than 
> a serial field. I have a stored procedure that allocates keys, based on 
> a built-in sequence but it also optionally adds suffixes, prefixes and 
> in some cases for particular tables it generates a Microsoft GUID.
> 
> Secondly, the data in your priv (and on your form) is not connected to 
> the database. The only connection should be
> You send data to the database - the database processes the data
> You request data from the database - the database sends it to priv.
> 
> If you want to update the display, you need to re-request the data from 
> the database. On some forms, like a day-planner for schedulers, I had a 
> timer which would do a query and refresh the screen automatically. 
> That's also why I pushed record updates from a tableframe to the 
> database on postrecord. First I'd try the db update, if it worked I'd do 
> the post and unlockrecord, if not I'd undo the changes on the TF. But 
> you could set a change flag and do the update all at once. In that case, 
> you need record versions on the database. Include the version when you 
> extract the data then, when you update, check the version first. 
> Remember, when you lock a record on the screen, the database record 
> isn't locked as well. It can be changed by someone else. Then we have 
> transactions, clean reads, dirty reads and all the reads in between. 
> Hehehehehe. You'll get to those. They are immensely useful and powerful.
> 
> Mark Bannister wrote on 5/02/2019 9:12 AM:
>> Also, I'm playing with PostgreSQL 11 and using the serial datatype for 
>> key fields. Interactively on a form pdox will not update the display 
>> of the key field if a new records is inserted. Actually it does on the 
>> first insert but not subsequent ones.  I have to close and open the 
>> form to see the new records.
>> If I use a Tcursor I must enter data into some other field and unlock 
>> to get the key field to be updated.  I see your stored procedure call 
>> in your sample library.  was it an attempt to get around this?
>>
>> The forceRefresh() call does not seem to do anything.
>>


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