On Wed, Jun 8, 2011 at 6:37 AM, Edward Brekelbaum <nedb...@yahoo.com> wrote:
> Hello, > Let me start by saying using SQLite in Tcl is a real pleasure! > > > I am having a problem determining when to use $ and when to use @ (and > maybe I > should use :, but I haven't tried it). > You should always use $, except when you want to insert a blob when you might consider using @, though $ will likely work in that case too. @ should only be used in the rare case when you have a TCL variable that has both a string representation and a bytearray representation and you want to use the bytearray representation and insert it as a blob. > > > > I have three tables: terrain(x,y), detail(id integer primary key > autoincrement, > x, y), and units(id ipka, detailId foreign) > (there are other fields but they are all untyped and not used for anything > but > filtering and retrieval). > > I started using $ everywhere, but sometimes had problems where I needed a > layer > of [subst] before calling eval. > > Then, I converted everything to @, but then some queries wouldn't match. I > needed to replace = with like, or insert casts. > > Right now, I have a mix of @ and $. I use @ for inserts and matches on > most > fields. I use $ to match detail.id and units.id. Comparing detail.id and > units.detailId requires a cast (because I insert into units.detailId with > @). > Also, I seem to be unable to match columns to string constants (I guess, > because > everything is a blob). > > > It seems to be related to the "impedance mismatch" mentioned on the Tcl > wiki. > > > > Is there some document that describes a best known method for dealing with > all > this? > > Thanks! > Ned > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
