odbcconn.Execute and SQL_NO_DATA
lazarus / 16-Databases

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Lacak2 · 2009-04-21 11:03

MSDN:
If SQLExecute executes a searched update or delete statement that does
not affect any rows at the data source, the call to SQLExecute returns
SQL_NO_DATA.

But ODBCCheckResult throws exception, because in ODBCSucces we do not
handle SQL_NO_DATA as success.

So I am unable to run sql statement that, does not affect any rows
without throwing exception.
What about adding " or (Res=SQL_NO_DATA)" into ODBCSucces or into
ODBCCheckResult ?

TIA
-Laco.

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Loesje · 2009-04-21 17:33

I don't think it's ok on all places where ODBCSucces is called. See if
you can find out.

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LacaK · 2009-04-22 06:57

I searched MSDN for return values of ODBC API functions. If I am
correct, there are only this functions (used in odbcconn.pas), which
can return SQL_NO_DATA:

1. SQLDriverConnect - If the user cancels a dialog box presented by
the Driver Manager or the driver - so this is not success

2. SQLGetData - when retrieving Variable-Length Data in Parts and no
more data is available - this should be handled into code, if not it
may indicate error

3. SQLFetch - expected and handled

4. SQLExecute - expected, not handled correctly

So I think, that we can handle this without touching ODBCCheckResult
or ODBCSucces ... in Execute method.
Please look at attached file.

-Laco.

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Loesje · 2009-04-22 08:21

Can't you make a normal patch?

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Lacak2 · 2009-04-22 12:35

It was not intended as a patch only as a proposed solution for
considering.

Although I have no experience with SVN and SVN utils, so I am not able
to prepare such patch (withou installing soem SVN and downloading
Lazarus from SVN).

I can make only diff between original file and my modification (but I
do not known if it is sufficient and if it is correct patch or not).
So diff will help ?

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Loesje · 2009-04-24 22:07

Yes, a diff is what I want. (Diff -u)

That's not because I want to apply it directly to svn, but I'm used to
read diff's, it's much easier to see what has been changed in a diff,
then when you have to compare two text-blocks which each other. (With
a diff I can judge it immediately, I don't even need to lookup the
original code, because that's also in the diff)

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LacaK · 2009-04-27 06:22

ok, here are two diffs. One build using Lazarus , second using cygwin
diff. hope this help.
Do you prefer also fill bug report in mantis bug tracker ?