revDataFromQuery : size limit of mySQL query ?

Peter Haworth pete at lcsql.com
Sat Jun 7 01:35:11 CEST 2014


Ah OK, sorry should have read more closely.

Don't know the answer to that one but if there is a limit the NOT IN thing
I suggested would cut down on the length of the SELECT statement since
there are no "AND" operators in it.


Pete
lcSQL Software <http://www.lcsql.com>
Home of lcStackBrowser <http://www.lcsql.com/lcstackbrowser.html> and
SQLiteAdmin <http://www.lcsql.com/sqliteadmin.html>


On Fri, Jun 6, 2014 at 3:06 PM, <jbv at souslelogo.com> wrote:

> Thanks fr the reply.
> Actually I'm pretty confident about the results of the query, as I have
> created very large results myself.
> My concern was more with the query itself...
>
> jbv
>
> > I haven't come across a limit and I've certainly created some very large
> > SELECT results but I guess there must be one at some point.
> > If you run into one, you can probably get round it by using
> > revQueryDatabase to create a cursor although that would probably mean
> > rewriting a lot of your code.
> >
> > One other unrelated suggestion.  I don't know if it's any more/less
> > efficient but you might try NOT IN ('John','Ted",...) in your SELECT
> > statement
> >
> > Pete
> > lcSQL Software <http://www.lcsql.com>
> > Home of lcStackBrowser <http://www.lcsql.com/lcstackbrowser.html> and
> > SQLiteAdmin <http://www.lcsql.com/sqliteadmin.html>
> >
> >
> > On Fri, Jun 6, 2014 at 12:52 PM, <jbv at souslelogo.com> wrote:
> >
> >> Hi list,
> >>
> >> Does anyone know if there is a limit in the length of the sql query
> >> when using revDataFromQuery ?
> >> According to what I found on the web, there doesn't seem to be
> >> any problem on mySQL side (default value is apparently 1 Mb),
> >> but I was more concerned by a possible buffer between LC and
> >> mySQL where the query could be truncated...
> >>
> >> Furthermore, I am fully aware that very long queries are hard
> >> to maintain and might lead to slow execution...
> >> What I have in mind in some rather simpler stuff like :
> >> SELECT name FROM myDB WHERE name != 'John' AND name != 'Ted'...
> >> where the list of names can be quite long...
> >>
> >> Thanks,
> >> jbv
> >>
> >>
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