On 6 Jan 2011, at 08:39, Andy Gibbs wrote: > On Thursday, January 06, 2011 9:09 AM, stunner Easwar wrote: > >> I need to use local variables similar to sql syntax using DECLARE. My >> project involves lot of places where I need to select values from >> different >> tables and insert it into one table. In most of the cases creation of view >> is also not feasible. Any alternative for DECLARE. > > As far as I am aware, there is no direct solution for what you want. If you > are willing to code some custom functions (see > http://www.sqlite.org/c3ref/create_function.html), then you could create a > workaround for yourself.
DECLARE is an extension which only works within stored procedures written in certain vendors' procedural SQL extensions. Since SQLite does not have any stored procedure facility (no CALL, no EXECUTE) the OP will need to redesign his/her application on a larger scale than the original question presumes; given that, why not remove the requirement for DECLARE at the same time? It will probably disappear naturally as the stored procedure logic is removed. If it is still required something like the API you suggested is about as good as you can get. You need a variable hashtable per connection. I would dispense with del_var and instead register commit and rollback hooks to clear out declared variables when the transaction which declared them ends; this is both more like the behaviour of DECLARE and is more defensive in that it will leave things tidy without requiring programmers to explicitly free their variables. Make sure that you define the behaviour of get_var when a variable of that name has not been set: I suggest that raising an error is the most useful thing you can do in this situation. Phil _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
