[Gambas-user] Problem with MySQL LONGTEXT field type

[Benoit Minisini]

On dimanche 14 décembre 2008, Luigi Carlotto wrote:
> Gambas2 - versione 2.9.0
>
> The single anomaly verification in a circumstance, that I will try to
> describe:
>
> - I have created a small static class that executes the logon to a
> database, executes query and returns the data in a structure much
> similar one to the logic applied to the Result/Field objects; at last
> the logon comes sluice.  This my logic is created in order to avoid to
> leave the logon open and, since the Result object maintains the data
> single to opened logon, my class copy these data in an appropriate
> structure of Array of objects, that it comes returned to the procedures
> that use this function.
> - the calling procedures use this class, that the structure returns
> given, that comes used for determined scopes.
> - the logons can be made on database PostgreSQL, MySQL and SQLite; the
> query they come correctly executed, returning the corrected values,
> unless for MySQL. Like described in the first mail, one of the query
> executes a loading of information from a table of system of MySQL, used
> in order to determine the structure of the database.
> - some fields of this table are of type “longtext” (BLOB).
> - Strangely, these fields return a value NULL, although their content is
> instead a valid data.
> - Verifying the Result object, immediately after the execution of the
> query, I have found that the value of this field is truly NULL, and this
> excludes an anomaly of my procedures.
> - To ulterior I have had confirmation, constructing it a small procedure
> of test, in which it executes the same operations made from my program,
> and that it uses the same static class; strangely, the query executed
> from the test program, it has given back a valid value in the field
> “longtest”.
> - The thing has made me to rise a doubt: since my program is rather
> complex, he is probable exists some problem in memory (stack) with the
> management of fields BLOB?
> - Knowing enough language C/C++, I have given to a glance to the code
> source of the library, but the only thing that I have found is that
> fields BLOB come managed in way detail, but has not found details
> conditions that could make me to doubt on they a wrong management.  The
> only thing that has come to me in mind, is perhaps that a problem of
> memory with programs exists many complexes, for which this type of data
> (blob) comes lost…
> - I have found this single anomaly in MySQL, but it is also true that
> the others dbms do not use this type of data (blob) in the system
> tables.
>
> Some suggestion?
>
> Thanks

Can you send me a little mysql database that implies some data in the ROUTINES 
table of information_schema?

-- 
Benoit Minisini