Transactions

[Skrim 11]

Hi

 

I have this code:

 

(Database is PostgreSql)

 

try

  aDatabase.starttransaction;

  ...

except

  on edatabaseerror do

  begin
    aDatabase.rollback;
  end;

end;

 

But what about a commit. Is it done automatically here, hence not necessary?

 

Regards,

Ole

Edited October 10, 2021 by Skrim
None

[haentschman 92]

Hi...

 

 try
  aDatabase.Starttransaction;
  ...
  aDatabase.Commit
except
  on edatabaseerror do
  begin
    aDatabase.Rollback;
  end;
end; 

Please use the "Code Tags" </> 

[Skrim 11]

21 minutes ago, haentschman said:

Hi...

 

 try
  aDatabase.Starttransaction;
  ...
  aDatabase.Commit
except
  on edatabaseerror do
  begin
    aDatabase.Rollback;
  end;
end; 

Please use the "Code Tags" </> 

Done.

 

Now, what is your answer to my question 

[David Heffernan 2345]

Just to be clear, what is aDatabase. I suppose the answer could depend on that information. 

[Skrim 11]

2 hours ago, David Heffernan said:

Just to be clear, what is aDatabase. I suppose the answer could depend on that information. 

It's a PostgreSql database.

[Skrim 11]

I have done some testing, it seems I do need a Commit.

 

Without it the data is not saved to the database.

 

So at least using Postgresql and you start a transaction, you either have to commit or rollback.

 

Ole

 

 

[Stano 143]

As far as I know, that is the basic role of transactions. It is about covering data integrity.

[Ruslan 5]

Is you are using FireDAC than transactions are used internally, but you could use transactions like in your example.

The "commit" is required if the the DataSet is set to no auto commit, e.g. cached updates.

 

If I am wrong please correct me.

[David Heffernan 2345]

2 hours ago, Skrim said:

It's a PostgreSql database.

 No. I mean what is aDatabase, the variable in your code. What is that? What type. 

[Hans J. Ellingsgaard 21]

If you use the StartTransaction command, you have to finish it off with CommitTransacton or a  Rollback. If you're not using a StartTransaction, the FDConnection will start it for you and make a commit when your datasets are closed.