[SOLVED] query.ChangeCount is always 0
lazarus / 16-Databases

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senglit · 2022-09-08 16:00

hi all,
I got something like this:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var 
dbConn: TSQLite3Connection;  trans: TSQLTransaction;  query:
TSQLQuery;        procedure
NewBox(sn:integer;name:string);var cc:integer=0;begin    query.Close; 
  query.SQL.Text :='insert into box(sn,name) values(' +sn.ToString +
',"' + Name + '")';    query.ExecSQL;    cc := query.ChangeCount;   
trans.Commit;    query.Close;end; 
After NewBox is called, with database browser I can see the new record
is added into the table "box". But I always got cc as 0. why?

ps: I tried with mysql5.7 and sqlite3, with both of these 2 database
type, I always got cc as 0.

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JanRoza · 2022-09-08 17:44

Maybe you have to commit first and after that assign the count to cc.

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Arioch · 2022-09-08 19:41

I wonder, what would you even expect there. It was always differently
named in Delphi

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    
query.ExecSQL;    cc := query.RowsAffected; 
See docs -
https://docs.getlazarus.org/#fcl+sqldb+tcustomsqlquery.rowsaffected#

And then when the trend became streamlining another pattern emerged:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i     cc :=
query.ExecSQL; 
ChangeCount ? What that even is, from what a library?

Is it perhaps a number of changes that were cached locally and NOT
sent to server, something along MIDAS library patterns, like
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
TDataset.Insert; TDataset.FieldByName('xxx').AsInteger :=
10;TDataset.Post;cc :=
TDataset.ChangeCount;TDataset.ApplyCachedUpdates;

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senglit · 2022-09-09 02:37

Yes, you are right. I should use RowsAffected instead of ChangeCount.
Problem solved. Thank you!

Quote from: Arioch on September 08, 2022, 09:41:40 pmI wonder, what
would you even expect there. It was always differently named in Delphi

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i    
query.ExecSQL;    cc := query.RowsAffected; 
See docs -
https://docs.getlazarus.org/#fcl+sqldb+tcustomsqlquery.rowsaffected#

And then when the trend became streamlining another pattern emerged:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i     cc :=
query.ExecSQL; 
ChangeCount ? What that even is, from what a library?

Is it perhaps a number of changes that were cached locally and NOT
sent to server, something along MIDAS library patterns, like
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
TDataset.Insert; TDataset.FieldByName('xxx').AsInteger :=
10;TDataset.Post;cc :=
TDataset.ChangeCount;TDataset.ApplyCachedUpdates;

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Zvoni · 2022-09-09 10:31

And use Parameters....
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var 
dbConn: TSQLite3Connection;  trans: TSQLTransaction;  query:
TSQLQuery;        procedure
NewBox(sn:integer;name:string);var cc:integer=0;begin    query.Close; 
  query.SQL.Text :='insert into box(sn,name) values(:psn,:pname)';   
query.ParamByName('psn').AsInteger:=sn;   
query.ParamByName('pname').AsString:=name;    query.ExecSQL;    cc :=
query.RowsAffected;    trans.Commit;    query.Close;end;

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Arioch · 2022-09-09 15:55

yeah, this too.

One day he can find a hard way that dates and times have different
human format with different programs and/or locales, or that NULL and
VOID sometimes are not surnames but something different, like one
american programmer learnt hard way :-)

https://bobby-tables.com/