gambas-devel

[Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[zxMarce <d4t...@gm...>]

Hi there. This is mainly intended to be tackled by Benoît, but anyone with
the necessary knowledge (Toby?) please feel free to butt in.

The ODBC driver can use Connection Strings since some time now. I also have
a patched up module that can run successfully non-data-producing queries
(the SQL_NO_DATA return code is no longer treated as an error), thanks to a
bug submitted by Piccoro.

Problem is in the open_database() function. When using connstrings, the
database name is usually part of this string, and no .Name property is
expected to be populated from the BASIC program, nor actually used.
So, I'm trying to populate the property from the ODBC backend. I can
successfully fetch the DB Name from the lower level database driver in use
(SQLite3 does not provide a name, tho, be warned).
What I cannot do, be it via copying char[] or Gambas String buffer pointers,
is to get the .Name property populated back to the running BASIC program.

The open_database() call has two parameters: DB_DESC *desc and DB_DATABASE
*db. My best guess is that I have to fiddle with desc, but not really sure
if that's correct nor exactly how.

To further salt the issue, queries exist in big RDBMS that allow to
hot-switch databases while connected to a server (example: USE <newDBName>
in MSSQL). So, the connection's .Name property should also be "refetched"
after a successful query is run.

Any suggestions?



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Re: [Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[<ada...@gm...>]

On Thu, 17 Aug 2017 17:26:26 -0700 (MST)
zxMarce <d4t...@gm...> wrote:

> (SQLite3 does not provide a name, tho, be warned).

Isn't a sqlite db without a name an "in memory" database?
b
-- 
B Bruen <ada...@gn... (sort of)>

Re: [Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[Benoît M. <ga...@us...>]

Le 18/08/2017 à 02:26, zxMarce a écrit :
> Hi there. This is mainly intended to be tackled by Benoît, but anyone with
> the necessary knowledge (Toby?) please feel free to butt in.
> 
> The ODBC driver can use Connection Strings since some time now. I also have
> a patched up module that can run successfully non-data-producing queries
> (the SQL_NO_DATA return code is no longer treated as an error), thanks to a
> bug submitted by Piccoro.
> 
> Problem is in the open_database() function. When using connstrings, the
> database name is usually part of this string, and no .Name property is
> expected to be populated from the BASIC program, nor actually used.
> So, I'm trying to populate the property from the ODBC backend. I can
> successfully fetch the DB Name from the lower level database driver in use
> (SQLite3 does not provide a name, tho, be warned).
> What I cannot do, be it via copying char[] or Gambas String buffer pointers,
> is to get the .Name property populated back to the running BASIC program.
> 
> The open_database() call has two parameters: DB_DESC *desc and DB_DATABASE
> *db. My best guess is that I have to fiddle with desc, but not really sure
> if that's correct nor exactly how.
> 
> To further salt the issue, queries exist in big RDBMS that allow to
> hot-switch databases while connected to a server (example: USE <newDBName>
> in MSSQL). So, the connection's .Name property should also be "refetched"
> after a successful query is run.
> 
> Any suggestions?
> 
> 

The open_database(DB_DESC *desc, DB_DATABASE *db) driver function takes 
two arguments:

- DB_DESC *desc : a pointer to a structure that contains all connections 
string properties and an integer option field.

- DB_DATABASE *db : a pointer to another structure that should be filled 
with all necessary information about the connection.

By modifying the desc fields, you are modifying the corresponding 
Connection object properties, as this is where they are stored.

But you must use GB.FreeString() and GB.NewString() to replace a string 
property value.

For example:

const char *new_value;

GB.FreeString(&desc->name); // Free the Gambas string containing the old 
database name

desc->name = GB.NewZeroString(new_value); // Create a new Gambas string 
from the zero-terminated string new_value, and store it.

That's it.

-- 
Benoît Minisini

Re: [Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[PICCORO M. L. <mck...@gm...>]

hi zxMarce and other, i want to mark a WARNING here.. as i can see too
many experience with mososoft SQL and must be some notes about some
other scalar HIGH DBMS..

sybase DOES NOT NEED A DB NAME TO HAVE A CONNECTION !
be warning: its not like sqlite that a db "in memory" are present at
least, here theres no connection, in same way db2 and oracle...

2017-08-17 21:25 GMT-04:00 Benoît Minisini via Gambas-devel
<gam...@li...>:
> const char *new_value;
>
> GB.FreeString(&desc->name); // Free the Gambas string containing the old
> database name
>
> desc->name = GB.NewZeroString(new_value); // Create a new Gambas string from
> the zero-terminated string new_value, and store it.

its great that can be changed the connection db on the fly for the
module.. its mandatory..

ok ODBC need! a connection db name when Established, but its only with
UnixODBC.. there's more "special behaviours"

* in same "host connection name" there are also "same many db names"
that its not the same as "in same host are many db names served"

that strange behaviour are applied to oralce and sybase, that runs "a
instance" of the software for "one or more than" databases... in the
same host..

due that PROPIETARY ODBC SOFTWARE CAN OFFERS A CONNECTION TO GAMBAS
WITHOUT A DATABASE VALID STRUCTURE, or a "empty valid connection" in
conclusion.. or more rare as succed to me, a connection but the db are
not the spected (due UnixODBC freedts can connect to a one db per host
at same time, as all here knowed. but it not limited to in real ysbae
or oracle)

>
> That's it.
>
> --
> Benoît Minisini
>
>
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Re: [Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[ML <d4t...@gm...>]

Benoît,

Thanks a ton. It looks way easier than I tried/thought... As usual.


Piccoro,

First off, I always default my examples to MSSQL because I work with
them, for good or bad. That's mainly what I have to try/test things from
Gambas.
But a single MySQL server -which is mostly free ($$$) IIRC- can also be
home to more than one DB/Catalog. Others may or may not follow suit.
Never tried Sybase, DB/2, or Oracle because I don't have access to
either. I rely on users to report inconsistencies like I had for
Firebird regarding RecordCount.

Never mind RDBMS that don't have a DB Name. The interface should be as
wide/general as possible, and if at least one of them uses or can switch
DB/Catalog names, then I think it should be supported.
Actually, SQLite3 (the one I do have at home, with your supplied example
of "CREATE IF NOT EXIST Tabla1...") fails to retrieve at least the DB
filename (test.sq3) as the Database/Catalog name.
That particular DB is a file, so I guess the driver should retrieve
*something* as DB Name but it does not, confusing everybody into
thinking it's an in-memory DB.

On the other hand, connstrings handle instances -at least with MSSQL-
transparently by specifying the instance in the server name, and this is
separate from the DB name.
So you can have any mix-n-match of servers, instances, and DBs, given
every server/instance has its own connection object.
Then you can switch DBs/Catalogs inside each Connection by running
MSSQL's USE (or the applicable RDBMS-specific) query command.


Regards,
zxMarce.

On 18/08/17 04:37, PICCORO McKAY Lenz wrote:
> hi zxMarce and other, i want to mark a WARNING here.. as i can see too
> many experience with mososoft SQL and must be some notes about some
> other scalar HIGH DBMS..
> sybase DOES NOT NEED A DB NAME TO HAVE A CONNECTION !
> be warning: its not like sqlite that a db "in memory" are present at
> least, here theres no connection, in same way db2 and oracle...
>
> 2017-08-17 21:25 GMT-04:00 Benoît Minisini via Gambas-devel
> <gam...@li...>:
>> const char *new_value;
>> GB.FreeString(&desc->name); // Free the Gambas string containing the
>> old database name
>> desc->name = GB.NewZeroString(new_value); // Create a new Gambas
>> string from the zero-terminated string new_value, and store it.
> its great that can be changed the connection db on the fly for the
> module.. its mandatory..
> ok ODBC need! a connection db name when Established, but its only with
> UnixODBC.. there's more "special behaviours" in same "host connection
> name" there are also "same many db names" that its not the same as "in
> same host are many db names served"
> that strange behaviour are applied to oralce and sybase, that runs "a
> instance" of the software for "one or more than" databases... in the
> same host..
> due that PROPIETARY ODBC SOFTWARE CAN OFFERS A CONNECTION TO GAMBAS
> WITHOUT A DATABASE VALID STRUCTURE, or a "empty valid connection" in
> conclusion.. or more rare as succed to me, a connection but the db are
> not the spected (due UnixODBC freedts can connect to a one db per host
> at same time, as all here knowed. but it not limited to in real ysbae
> or oracle)
>> That's it.
>> --
>> Benoît Minisini

Re: [Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[PICCORO M. L. <mck...@gm...>]

2017-08-18 7:22 GMT-04:00 ML <d4t...@gm...>:

> of "CREATE IF NOT EXIST Tabla1...") fails to retrieve at least the DB
> filename (test.sq3) as the Database/Catalog name.
> That particular DB is a file, so I guess the driver should retrieve
> *something* as DB Name but it does not, confusing everybody into


that's the behaviour that i try to explain... DBMS connection "intance"
dont have to handle a db "instance" that's behaviour its copied from M$ in
mysql and postgres but DBMS in the connections dont must handle a db
"instance" and that's correct... but ODBC M$ especifications said that
must.. this king of "rare" conflicts its common in documents where M$ are
involved!

Re: [Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[Benoît M. <ga...@us...>]

Le 18/08/2017 à 14:39, PICCORO McKAY Lenz a écrit :
> 
> that's the behaviour that i try to explain... DBMS connection "intance" 
> dont have to handle a db "instance" that's behaviour its copied from M$ 
> in mysql and postgres but DBMS in the connections dont must handle a db 
> "instance" and that's correct... but ODBC M$ especifications said that 
> must.. this king of "rare" conflicts its common in documents where M$ 
> are involved!
> 

I have no idea what you try to tell us, your english is absolutely 
unreadable.

Please try to make some effort!

Can't you, at least, install an english spelling checker on your mail 
client or your browser? It would be a good start.

As for the grammar, I don't know if there is a grammatical corrector for 
english on Linux.

Regards,

-- 
Benoît Minisini

Re: [Gambas-devel] Cannot populate database Connection.Name from ODBC driver.

[PICCORO M. L. <mck...@gm...>]

umm okok, write in the browser event in the console:

2017-08-18 7:22 GMT-04:01 ML <d4t...@gm...>:

> of "CREATE IF NOT EXIST Tabla1...") fails to retrieve at least the DB
> filename (test.sq3) as the Database/Catalog name.
> That particular DB is a file, so I guess the driver should retrieve
> *something* as DB Name but it does not, confusing everybody into


that's the behaviour that i try to explain... a DBMS connection "instance"
don't have to handle a db "instance", that's behaviour found on DBMS's such
like postgres or mysql inherits from the "M$" era but are not mandatory...

but in many propietary DBMS the connections dont "must handle" a db
"instance" and that's correct... in some place the ODBC especification said
that a db name must be provided, but mayor DBMS dont need a db name
provided, that's behaviour are found commonly in Oracle, Firebird, Sybase,
SAP and many other, almost all the propietary DBMS do in this way...



Lenz McKAY Gerardo (PICCORO)
http://qgqlochekone.blogspot.com

2017-08-18 8:51 GMT-04:00 Benoît Minisini <ga...@us...>:

> Le 18/08/2017 à 14:39, PICCORO McKAY Lenz a écrit :
>
>>
>> that's the behaviour that i try to explain... DBMS connection "intance"
>> dont have to handle a db "instance" that's behaviour its copied from M$ in
>> mysql and postgres but DBMS in the connections dont must handle a db
>> "instance" and that's correct... but ODBC M$ especifications said that
>> must.. this king of "rare" conflicts its common in documents where M$ are
>> involved!
>>
>>
> I have no idea what you try to tell us, your english is absolutely
> unreadable.
>
> Please try to make some effort!
>
> Can't you, at least, install an english spelling checker on your mail
> client or your browser? It would be a good start.
>
> As for the grammar, I don't know if there is a grammatical corrector for
> english on Linux.
>
> Regards,
>
> --
> Benoît Minisini
>