Use a prepared statement. Dynamically constructing SQL is a serious
security loophole and a performance dog.

I am not certain of the syntax for your language, but here it is in
Java. It is similar in Delphi.

// in application initialization
stmt = connection.prepare ("INSERT INTO MYTABLE (MYDATE) VALUES (?)");

/* snip ... */
// in use ...
stmt.clear();
if ((myDate == null) || (myDate.equals ("NULL")))
{
stmt.setNull (1); /* setting null is different from not setting a
param */
}
else
{
stmt.setString (1, myDate); /* JDBC handles the String to Date
conversion */
}

result = stmt.executeQuery ();

On Tue, 2005-12-13 at 18:59 -0800, Lin XG wrote:
> Hi Jason;
>
> myDate is a string.
>
> Thanks for the tip, but it doesn't work.
>
> If I use 12/13/05 10:00 the query will look like
>
> INSERT INTO MYTABLE (MYDATE) VALUES ('12/13/05
> 10:00');
>
> If I use "NULL" the query comes out looking like
>
> INSERT INTO MYTABLE (MYDATE) VALUES ('NULL');
>
> which generates a string conversion error.
>
> Still scratching my head.
>
> Lin
>
> --- Jason Dodson <jasond@...> wrote:
>
> > Is MyDate a Variant?
> >
> > Anyway, set MyDate = "NULL", quotes and all. The SQL
> > will work fine as long as
> > MyDate holds the STRING "NULL", not a NULL value.
> >
> > Jason
> >
> > sbdlinxg wrote:
> > > I've just discovered Firebird and I'm using VB to
> > experiment with it.
> > > This code works fine
> > >
> > > myDate = Format(Now(), "mm/dd/yy hh:mm")
> > > sql = "INSERT INTO MYTABLE (MYDATE) VALUES ('" &
> > myDate & "');"
> > >
> > > as long as myDate is a date. If I set myDate =
> > NULL the statement
> > > causes an error and I know why the error is
> > occurring.
> > >
> > > What I need to know is how to write this statement
> > to take into
> > > account the possibility that myDate is NULL.
> > >
> > > Thanks
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
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