Fix #30 - Created rule G-7330: Always assign values to OUT parameters.

Author: kibeha

docs/4-language-usage/7-stored-objects/3-procedures/g-7330.md

@@ -0,0 +1,39 @@
+# G-7330: Always assign values to OUT parameters.
+
+!!! tip "Major"
+    Maintainability, Testability
+
+## Reason
+
+Marking a parameter for output means that callers will expect its value to be updated with a result from the execution of the procedure. Failing to update the parameter before the procedure returns is surely an error.
+
+## Example (bad)
+
+``` sql
+create or replace package body my_package is
+   procedure greet(
+      in_name      in  varchar2
+    , out_greeting out varchar2
+   ) is
+      l_message varchar2(100);
+   begin
+      l_message := 'Hello, ' || in_name;
+   end my_procedure;
+end my_package;
+/
+```
+
+## Example (good)
+
+``` sql
+create or replace package body my_package is
+   procedure greet(
+      in_name      in  varchar2
+    , out_greeting out varchar2
+   ) is
+   begin
+      out_greeting := 'Hello, ' || in_name;
+   end my_procedure;
+end my_package;
+/
+```