[Mysql-cocoa-users] Re: SMySQL framework

[Lorenz T. <lo...@te...>]

Dear Serge,

Thank you very much for taking the time to respond so detailed.

> Sorry not to have answered earlier. I'll try to give you as much info=20=

> as I can:
As you see I had much longer to answer (I was in holidays and hadn't=20
the possibility to check my emails ;-)

> For the SSL issue:
> I'm afraid I can not answer the question for sure. What I can tell you=20=

> is that on Jaguar (10.2.3 indeed) I managed to compile MySQL with SSL=20=

> support (including the libmysqlclient library onn which I rely to make=20=

> connection to MySQL servers). This means that even if it is not=20
> already possible to use the framework as is for connecting to MySQL=20
> using SSL, it should not be too difficult to get to this point.
> For the answer of how to manage to do it, I can suggest to ways:
>  1. Look the documentation of MySQL (client library) and check what is=20=

> required to have a SSL connection. Maybe you need to set a particular=20=

> flag from the MYSQL pointer. Than you can do it by default (changing=20=

> default in the source of the framework).
I found in the documentation that I can set the flag CLIENT_SSL in the=20=

mysql_real_connect() function. By now I have no possibility to test it=20=

because I have not set up my system to work with SSL. If I will find=20
the time, I'll try to set up a test server and test it with your=20
framework.
>  2. You can also add a method to MCPConnection to be able to set this=20=

> option at runtime.
I would make it like this, because the standard way to connect would=20
remain without SSL.
>  3. If you can still wait a month (or maybe a bit more), you can wait=20=

> for me to have the time to make it. I need this time because I have a=20=

> lot of work now and I also need to set a SSL aware MySQL server to=20
> test the new sources... which will take a bit of time for me because=20=

> I've never done anything similar alreasdy (basically the time to read=20=

> doc, reset properly the setting of my testing server, and then ONLY I=20=

> can modify the MCPConnection...).
>
> By the way, if you chose sol. 2. I'm (obviously) interested by the=20
> modification you make to MCPConnection for further inclusion in the=20
> framework (more likely as the basis of new addition to the framework).
I would be glad to help you with this modifications, but unfortunately=20=

I also haven't a lot of time to work on these things (and it would take=20=

me a lot of time to set up SSL because I never worked with it, and I am=20=

rather a Unix newbie too...).
>
> For the table type:
> I don't have precise answer here neither... BUT I have InnoDB running=20=

> on my mac, and event if so far I've never used through the framework,=20=

> it should not be to hard for me to test it. SO I'll try to give you a=20=

> documented answer in the coming two weeks (still I don't foresee any=20=

> reasons for that 'incompatibility', ie. my guess would be that the=20
> problem does not come from the framework).
I'm nearly sure that this is a problem of the MySQL server=20
configuration. But I never worked with this tables and therefore I=20
can't be sure of this. If you could try it (maybe with my app), it=20
would be great, but it isn't that important or urgent.

> For the last question I'm not sure to get it right. Let me try to=20
> rephrase it (and tell if I'm wrong):
> When you retrieve a BLOB (or TEXT) from the DB it comes as a NSData=20
> object. You want this NSData object to be (eventualy) edited as text=20=

> by the user. The problem you are facing is that if you transform this=20=

> NSData to a NSString and convert it back to a NSData later the two=20
> NSData are different (so if your NSData correspond to a binary format,=20=

> the data gets corrupted).
It is exactly like this. The string I get from the NSData is for=20
example like this:
GIF89a=03=01 plus a lot of strange characters
After writing it to the db, there is only the GIF89a=03=01 without the =
rest=20
of the string (although I escaped the string using the method=20
prepareString:). I think the method I use to extract the string=20
([[NSString alloc] initWithData:theValue encoding:[mySQLConnection=20
encoding]]) is wrong.
Maybe the problem is that the string contains characters which=20
"terminate" the string, for example if I insert the string in a text=20
file, I don't see anymore the cursor or the end of the file. The same=20
thing happens with the dump files my app writes; there I use the method=20=

prepareBinaryData: with the original NSData objects. Reading the dump=20
afterwards works fine, but when I open the file using TextEdit, it=20
displays only the beginning of the file.

>
> If this is the problem you are facing... I'll have a look to see what=20=

> can we do about it. The main problem I'm facing with TEXT and BLOB=20
> column in a table is that one can not discriminate between the two (or=20=

> at least I don't know how to do it) without issuing a 'DESCRIBE'=20
> command on the table (they give the same type in the MYSQL_RES field=20=

> types).
> Indeed after seeing the framework again I think the normal solution=20
> would be not to use prepareBinaryData: but prepareString: instead. ie=20=

> once your NSData has been transformed into a string (By the way you=20
> can use the method stringWithText: for that), you don't want to use=20
> prepareBinaryData on it anymore.
I'm using the method prepareString:, but it doesn't work. What is the=20
method stringWithText:? I haven't found it in the documentation.

Anyway, this isn't very important because it works well with "normal"=20
(non binary) blob fields and some binary blob fields too; and it=20
doesn't make much sense to edit a binary data as a string. Dumping the=20=

table or editing a row containing this blob fields works well too.

>
> Sorry for not answering your question (still I hope you get some=20
> clues), thank you very much for your feed back, and I'd hope we will=20=

> continue this thread whenever we have time (meaning: sorry in advance=20=

> if I take some time to answer to your next mail).
Thank you for helping me and for developing the framework! I would be=20
glad to continue this thread too, but I will also need a bit of time to=20=

answer ;-)

> Serge.
>
> PS: As you see, I posted this also to the user mailing list. Please=20
> I'd like that all these mails go there instead of directly to me. I AM=20=

> READING the list, and I'm not the only one (from the number of people=20=

> inscribed there). I'm sure some of the few persons there might have=20
> already experienced some of your problems and can help you (and me at=20=

> the same time).
I will make it like this starting with this email!
> PPS: I'd be interested to know which version of the framework you are=20=

> using, and on what version of your own software you already are.
The version I use is still the beta of the version 1.0. I would like to=20=

update to v2.0, but I haven't found the time to make the necessary=20
changes to my code (especially I would have to test the app very=20
carefully to be sure that all things work like they worked before).=20
Anyway, all the methods I use in my app work perfectly!
The current version of my CocoaMySQL is v0.4 (which I will release=20
after some final testing this evening or tomorrow). You find it on=20
cocoamysql.sourceforge.net if you are interested...
> PPPS: last remark: If the problem is the very (very) low traffic on=20
> the mailing list, just consider that the traffic has to start on some=20=

> time...
That's right. I have subscribed to it today and will try to contribute=20=

to the list as much as I can!
>
> PPPPS: Sorry one more: remind me of linking to your project from the=20=

> framework page if it is not already done.
This would be great! I have placed a link to the framework page=20
(http://mysql-cocoa.sourceforge.net/) on my site (hope this is the=20
right page).

Best Regards,
Lorenz

>
> Le mercredi, 19 f=E9v 2003, =E0 10:13 Europe/Amsterdam, Lorenz Textor =
a=20
> =E9crit :
>
>> Hi Serge,
>>
>> As I wrote to you some months ago I'm developing an application=20
>> called CocoaMySQL using your framework to connect to the MySQL server=20=

>> (see cocoamysql.sourceforge.net). Thanks again for coding this great=20=

>> framework and for making it open-source!
>>
>> I have some questions regarding the framework:
>> - Many persons asked me if it is possible to connect securely to the=20=

>> MySQL server using SSL. I looked a bit at the MySQL C API and think=20=

>> there is an option to do it. Would it be difficult to change the=20
>> framework so that secure connections are possible? Or is it possible=20=

>> with the current version yet?
>> - Some people wrote me they have problems using other table types=20
>> (InnoDB for example). Can this be a problem of the framework?
>> - How can I represent a BLOB field (NSData object) as a string that=20=

>> can be edited and saved to the database afterwards? I don't want the=20=

>> string to be escaped, so I can use prepareBinaryData: only after=20
>> editing. Now I'm using something like
>> 	[[NSString alloc] initWithData:theData encoding:[mySQLConnection=20=

>> encoding]];
>> In most cases this works, but with binary data (for example images)=20=

>> the data gets corrupted.
>>
>> Thank you for your help!
>> Best Regards,
>> Lorenz
>>
>>
>>
> ----------------------------------------------------
> Serge Cohen
>
> GPG Key ID: Non-Available for the moment.
> ----------------------------------------------------
>
>

--=20
lorenz textor
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