[ADD] Raise history sample

Author: stivenramireza

classes/33-store-procedures.sql

@@ -17,3 +17,43 @@ CALL insert_region_proc(5, 'Central America');
 
 SELECT *
 FROM regions;
+
+-- Create a raise history
+CREATE OR REPLACE PROCEDURE controlled_raise (percentage NUMERIC) AS $$
+DECLARE
+	real_percentage NUMERIC(8,2);
+	total_employees INT;
+BEGIN
+	real_percentage = percentage / 100;
+
+	-- Save the historical records
+	INSERT INTO raise_history (date, employee_id, base_salary, amount, percentage)
+	SELECT 
+		CURRENT_DATE,
+		employee_id,
+		salary,
+		max_raise(employee_id) * real_percentage,
+		percentage
+	FROM employees;
+
+	-- Update the employees table
+	UPDATE employees
+	SET salary = salary + (max_raise(employee_id) * real_percentage);
+
+	SELECT COUNT(*) INTO total_employees
+	FROM employees;
+
+	RAISE NOTICE 'Affected % employees', total_employees
+
+	COMMIT;
+
+END;
+$$ LANGUAGE plpgsql;
+
+CALL controlled_raise(1);
+
+SELECT *
+FROM employees;
+
+SELECT *
+FROM raise_history;

resources/12-raise-history.sql

@@ -0,0 +1,16 @@
+DROP TABLE IF EXISTS "public"."raise_history";
+-- This script only contains the table creation statements and does not fully represent the table in the database. It's still missing: indices, triggers. Do not use it as a backup.
+
+-- Sequence and defined type
+CREATE SEQUENCE IF NOT EXISTS raise_history_id_seq;
+
+-- Table Definition
+CREATE TABLE "public"."raise_history" (
+    "id" int4 NOT NULL DEFAULT nextval('raise_history_id_seq'::regclass),
+    "date" date,
+    "employee_id" int4,
+    "base_salary" numeric(8,2),
+    "amount" numeric(8,2),
+    "percentage" numeric(4,2),
+    PRIMARY KEY ("id")
+);