On 13 Jul 2011, at 1:13pm, Amit Chaudhuri wrote: > I have situation where a column may contain prices (REAL) or a string > meaning "no price for this, sorry." I can handle this in application code > but was wondering if I am overlooking a Sqlite feature which might do the > same out of the box: perhaps a TYPE( ) or an IsText( ) function..?
There is a 'typeof'. But you didn't know the proper way to do it. What you do is set up the column to be a number format (real or integer, however you hold your prices) and use NULL when you don't have a price. Then you can very quickly and easily check for a NULL with typeof(X) = 'null' nullif(X,Y) or convert it to your 'no price for this' string with ifnull(X,'No price for this, Sorry.') In fact this is what NULL means in SQL: something like 'data missing' or 'value unknown'. So it is exactly what you really want. For more details see <http://www.sqlite.org/lang_corefunc.html> For how to do calculations on numbers that might be NULL, see <http://www.sqlite.org/lang_aggfunc.html> For more details than you need don't bother seeing <http://www.sqlite.org/nulls.html> Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
