oracle重载操作符的例子

转自：http://download.oracle.com/docs/cd/B13789_01/server.101/b10759/statements_6004.htm

 

Creating User-Defined Operators: Example

This example creates a very simple functional implementation of equality and then creates an operator that uses the function:

CREATE FUNCTION eq_f(a VARCHAR2, b VARCHAR2) RETURN NUMBER AS
BEGIN
   IF a = b THEN RETURN 1;
   ELSE RETURN 0;
   END IF;
END;
/

CREATE OPERATOR eq_op
   BINDING (VARCHAR2, VARCHAR2) 
   RETURN NUMBER 
   USING eq_f;