G-2135: Avoid assigning values to local variables that are not used by a subsequent statement.
Major
Efficiency, Maintainability, Testability
Reason
Expending resources calculating and assigning values to a local variable and never use the value subsequently is at best a waste, at worst indicative of a mistake that leads to a bug.
Example (bad)
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20 | create or replace package body my_package is
procedure my_proc is
co_employee_id constant employees.employee_id%type := 1042;
l_last_name employees.last_name%type;
l_message varchar2(100 char);
begin
select emp.last_name
into l_last_name
from employees emp
where emp.employee_id = co_employee_id;
l_message := 'Hello, ' || l_last_name;
exception
when no_data_found then
null; -- handle_no_data_found;
when too_many_rows then
null; -- handle_too_many_rows;
end my_proc;
end my_package;
/
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Example (good)
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22 | create or replace package body my_package is
procedure my_proc is
co_employee_id constant employees.employee_id%type := 1042;
l_last_name employees.last_name%type;
l_message varchar2(100 char);
begin
select emp.last_name
into l_last_name
from employees emp
where emp.employee_id = co_employee_id;
l_message := 'Hello, ' || l_last_name;
message_api.send_message(l_message);
exception
when no_data_found then
null; -- handle_no_data_found;
when too_many_rows then
null; -- handle_too_many_rows;
end my_proc;
end my_package;
/
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