ansi sql

hi, I'm just starting with Informix (v. 7.3), and got a few questions. 1. is there a predefinied function to check if the value of variable is a date? is there a predefinied function to check if the value of variable is decimal? assume, that in both cases variables are declared as a VARCHAR. 2. is a easy and cheap way to convert VARCHAR to DEC (predefinied function). cause, there's a function: Date(VARCHAR) returning DATE all the best CN

CN wrote: > I'm just starting with Informix (v. 7.3), and got a few questions. > > 1. is there a predefinied function to check if the value of variable > is a date? > is there a predefinied function to check if the value of variable > is decimal? > > assume, that in both cases variables are declared as a VARCHAR. I don't think so. In either case, it is not desparately hard to write a stored procedure to do the job, though handling the error on a failed conversion requires some management. Also, do you want the converted date/decimal as the returned value, with NULL on failure, or something else? -- untested code -- CREATE PROCEDURE is_date(v VARCHAR(30)) RETURNING DATE; DEFINE d DATE; ON EXCEPTION RETURN NULL; END EXCEPTION LET d = v; RETURN d; END PROCEDURE; With 7.3, the TO_DATE() function may do what you need -- my 5.00 manual doesn't cover that. > 2. is a easy and cheap way to convert VARCHAR to DEC (predefinied > function). > cause, there's a function: Date(VARCHAR) returning DATE The analogue of the is_date() function above is easy enough to use. Also, a lot of the time you can simply get away with: str + 0.0 -- Jonathan Leffler (jleffler@informix.com, jleffler@earthlink.net) Guardian of DBD::Informix v0.62 -- see http://www.perl.com/CPAN #include <disclaimer.h>