Board index » delphi » D7.1 TSQLConnection issue w/MySQL

2004-05-17 07:05:19 PM
delphi84
uses D7.1, MySQL 3.23.58
to whom,
I am not sure if this exposes a bug, fix, feature, or simply bad
programming on my part, but it broke my code, and I'd
like to see what people think.
before D7.1, this worked:
SQLConnection1.Open; // initial parameters point at OldDataBase
// do some things
SQLConnection1.Params.Values['Database'] := 'NewDataBase';
SQLConnection1.GetTableNames(ListBox1.Items, False);
// Listbox contains list of tables in NewDataBase
after D7.1
ListBox contains list of tables in OldDataBase :(
the only way I can seem to make it read the table list correctly
is to close and re-open the SQLConnection.
comment?
-paladin
 

To be honest, I am skeptical that the pre-7.1 result was as you say, but
when I get a chance I will test it.
As for your 7.1 results, they are IMHO entirely correct.
H
"paladin" <XXXX@XXXXX.COM>writes

Connection Params such as Database,... should be set before Open. In your
case do a Close and Open connection to the new database to get the new list
of tables.
T.Ramesh.
"paladin" <XXXX@XXXXX.COM>writes

are you skeptical enough to wager an enormous amount of money?
-paladin
"Hugh Jones" <XXXX@XXXXX.COM>writes news:40a8a748$XXXX@XXXXX.COM...

ramesh,
but doesn't closing and re-opening the connection go through
the entire MySQL login/password sequence again? Seems
like alot of overhead for something so simple, especially when
we have a property like KeepConnection?
The app that got broken is a db-explorer type thing that lists
all available databases and tables on a MySQL server.
I do not mind implementing your suggestion, nor do I mean
to pester you with questions. Just trying to learn from the masters...
-paladin
 

Execute this sql before to get the table names:
"use <newdatabase name>"
Regards,
Cristian Nicola
"paladin" <XXXX@XXXXX.COM>writes

Forgot to mention .. while you are at it could you give it a try to
microolap.com/dbx/mysql/index.htm
Regards,
Cristian Nicola
"paladin" <XXXX@XXXXX.COM>writes

Paladin,
You could also try the suggestion by Cristian to use "Use database" rather
than disconnecting from the database.
T.Ramesh.
"paladin" <XXXX@XXXXX.COM>writes

cristian
thankyou, the 'Use' idea seems to work. I recall evaluating your
microOLAP drivers back when I first started with D6, but rejected
them for ?? (can't remember) reason[s]. certainly cost was one.
I'd like to re-evaluate but the link to download the demo:
microolap.com/dbx/mysql/dbx4mysql.zip
seems to result in a file that is not a valid zip archive?
interestingly enough (or should I say, skeptically enough?),
simply issuing a close in between gettablenames seems to
work also, eg.
SQLConnection1.Params.Values['DataBase'] := 'DB_ONE';
SQLConnection1.GetTableNames(ListBox1.Items);
SQLConnection1.Close;
SQLConnection1.Params.Values['DataBase'] := 'DB_TWO';
SQLConnection1.GetTableNames(ListBox2.Items);
SQLConnection1.Close;
SQLConnection1.Params.Values['DataBase'] := 'DB_THREE';
SQLConnection1.GetTableNames(ListBox3.Items);
implying that GetTableNames opens the connection and
leaves it open.
-paladin
 

:)
No.
But I am going to test it.
H
"paladin" <XXXX@XXXXX.COM>writes

The archive is ok.. please try to download it again..
Cristian
"paladin" <XXXX@XXXXX.COM>writes

Perhaps I meant 'surprised' rather than skeptical.
 

Who are you writing to?
Cristian Nicola
"Hugh Jones" <XXXX@XXXXX.COM>writes

Cristian, my response was for paladin.
"Cristian" <XXXX@XXXXX.COM>writes

"Hugh Jones" wrote
years of dealing with dbexpress and midas bugs and
no source code, any nerve endings that *could* be
irritated are now covered with deep scar tissue.
and will you answer back here?
tia,
pal