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條款五十九，嘗試使用 RETURNING INTO，而非使用 Using OUT 綁定輸出參數。

像是下面這段程式使用了 Using OUT 語法去綁定輸出參數就不被建議。

CREATE OR REPLACE PACKAGE BODY employee_api IS 
  PROCEDURE upd_salary (in_employee_id IN employees.employee_id%TYPE ,in_increase_pct IN types_up.percentage ,out_new_salary OUT employees.salary%TYPE) 
  IS 
    co_sql_stmt CONSTANT types_up.big_string_type := ' UPDATE employees SET salary = salary + (salary / 100 * :1) WHERE employee_id = :2 RETURNING salary INTO :3'; 
  BEGIN 
    EXECUTE IMMEDIATE co_sql_stmt 
    USING in_increase_pct, in_employee_id, OUT out_new_salary; 
  END upd_salary; 
END employee_api; /

建議的做法是用 RETURNING INTO 語法去綁定輸出參數。

CREATE OR REPLACE PACKAGE BODY employee_api IS 
  PROCEDURE upd_salary (in_employee_id IN employees.employee_id%TYPE ,in_increase_pct IN types_up.percentage ,out_new_salary OUT employees.salary%TYPE) 
  IS 
    co_sql_stmt CONSTANT types_up.big_string_type := 'UPDATE employees SET salary = salary + (salary / 100 * :1) WHERE employee_id = :2 RETURNING salary INTO :3'; 
  BEGIN 
    EXECUTE IMMEDIATE co_sql_stmt 
    USING in_increase_pct, in_employee_id 
    RETURNING INTO out_new_salary; 
  END upd_salary; 
END employee_api; /