Hello. Another thing that you can try is the use the describe table query to get the table schema and parse it. Once done you can check whether column exists or not.
With Regards Irtiza Ali On 6 Feb 2018 21:35, "Oliver Ruebenacker" <cur...@gmail.com> wrote: > Thanks for the response! > > So, the best solution I can come up with is catching the > InvalidQueryException and check whether its message contains the phrase > "conflicts with an existing column". Seems to work, but super-ugly. > > I do assume that in general, if a request fails, it does not permanently > change the data in Cassandra, right? > > It would be great if alter-add could have an if-not-exists clause. Would > that be hard to implement? > > I could not find a standard CQL way of asking what columns exist. Did I > miss it? Would it be hard to implement? > > I get that we're only eventually consistent anyway. > > Thanks! > > Best, Oliver > > On Mon, Feb 5, 2018 at 5:12 PM, Rahul Singh <rahul.xavier.si...@gmail.com> > wrote: > >> Yeah, you can handle the exception — what i meant that it wouldnt cause >> harm to the DB >> >> -- >> Rahul Singh >> rahul.si...@anant.us >> >> Anant Corporation >> >> On Feb 5, 2018, 5:07 PM -0500, Oliver Ruebenacker <cur...@gmail.com>, >> wrote: >> >> Well, it does throw an InvalidQueryException if the column already exists. >> >> On Mon, Feb 5, 2018 at 4:44 PM, Rahul Singh <rahul.xavier.si...@gmail.com >> > wrote: >> >>> Since CQL != SQL, there’s isnt a syntatical way. Just run the alter >>> table command and it shouldn't be an issue if its there. >>> >>> -- >>> Rahul Singh >>> rahul.si...@anant.us >>> >>> Anant Corporation >>> >>> On Feb 5, 2018, 4:15 PM -0500, Oliver Ruebenacker <cur...@gmail.com>, >>> wrote: >>> >>> >>> Hello, >>> >>> What's the easiest way to add a column to a table but only if it does >>> not exist? Thanks! >>> >>> Best, Oliver >>> >>> -- >>> Oliver Ruebenacker >>> Senior Software Engineer, Diabetes Portal >>> <http://www.type2diabetesgenetics.org/>, Broad Institute >>> <http://www.broadinstitute.org/> >>> >>> >> >> >> -- >> Oliver Ruebenacker >> Senior Software Engineer, Diabetes Portal >> <http://www.type2diabetesgenetics.org/>, Broad Institute >> <http://www.broadinstitute.org/> >> >> > > > -- > Oliver Ruebenacker > Senior Software Engineer, Diabetes Portal > <http://www.type2diabetesgenetics.org/>, Broad Institute > <http://www.broadinstitute.org/> > >
