On 12/7/24 09:59, Igor Korot wrote:
Hi, Adrian,
On Sat, Dec 7, 2024 at 11:18 AM Adrian Klaver <adrian.klaver@xxxxxxxxxxx> wrote:
On 12/6/24 19:36, Igor Korot wrote:
Hi, All,
When my application starts up, ot creates some tables and insert records
in them.
When the app starts for the second time it should check if the tables
and the records in them are exist and skip the process.
Does this also apply to starts after the second time?
Yes, it does.
However, if the new table is created in the meantime - the new record
should be created, because it is not there yet.
What determines that a new table needs to be created and populated?
Is the data expected to change over time?
Data change is possible.
This is one of the tables:
"CREATE TABLE IF NOT EXISTS \"sys.abcatfmt\"(\"abf_name\" char(30)
NOT NULL, \"abf_frmt\" char(254), \"abf_type\" smallint, \"abf_cntr\"
integer" ));";
"CREATE UNIQUE INDEX IF NOT EXISTS pbcatf_x ON
\"sys.abcatfmt\"(\"abf_name\" ASC);";
My understanding is that "INSERT OR IGNORE" will check the unique
It is INSERT ... ON CONFLICT DO NOTHING | UPDATE.
index and will not do anything if the recrd
with such data on the index already exists.
So you have the option of either skipping the insert or updating
selected fields in the row.
Everything is good, except what if I have a connection from 2 different
users?
Is it possible to have the app start up without external users connecting?
Not sure what you mean here.
Are you asking if the computer can run the app?
Then the answer is NO. App is always started by the user.
Please clarify.
This is going to need a more detailed explanation of what 'app' means.
Are you talking about the front end that the user launches or the
backend that runs the database or something else?
Thank you.
I can run this inside transaction, but will this be enough? Will stating
transaction lock the DB and the second user will wait for transaction to
complete?
Thank you.
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
