V12 has introduced the possibility to initialize local variables within the DECLARE statement, such as
Now it would be fine if one could declare constants, too, (like "const int" in C/C++ etc.). This would be handy for longer blocks of code, e.g. to name savepoints or name expressions that are used in several queries.
And it might make explicit that a variable like in this question cannot be changed unintentionally...
I don't know if constants are defined in the SQL standards, so I won't suggest a particular syntax.
asked 31 Oct '10, 21:08
I like this idea and will discuss it with the SA development team for possible inclusion in a future release. Thanks for making the suggestion. As mentioned in Ivan's response to this question, the optimizer cannot use variable values when optimizing queries define within a stored procedure, but with the ability to mark a variable as constant (and if its value is, in fact, a constant) then there is the possibility that the optimizer could use the constant value at optimization time.
answered 01 Nov '10, 21:08