Tim Streater wrote: > If I have a text column defined as it might be as MYCOL TEXT (that is > with no default value)
All columns have a default value. With no _explicitly_ specified default value, the column's default value is NULL. > is there a way to distinguish ... between ... no data ... and ... the > empty string? When you have never entered data, the value is NULL, which is distinct from '', the empty string. As long as your program takes care to never confuse these two values, it is possible to assign the meaning "never entered data" to the NULL value and have it work as you want. (Please note that in SQL, the NULL value does _not_ have any predefined meaning such as "unknown" or "missing" or "invalid". SQL defines only how the NULL value behaves; it is your job as the programmer or database designer to determine if you can assign a meaning to the NULL value that matches this behaviour with the intended usage.) Regards, Clemens _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
