add: unions

sql/full_course/clause/unions.sql

@@ -0,0 +1,35 @@
+CREATE TABLE income (
+    income_id INT PRIMARY KEY AUTO_INCREMENT,
+    income_name VARCHAR(25),
+    amount DECIMAL(5,2)
+);
+
+CREATE TABLE expenses (
+    expense_id INT PRIMARY KEY AUTO_INCREMENT,
+    expense_name VARCHAR(25),
+    amount DECIMAL(5,2)
+)
+
+INSERT INTO income (income_name, amount)
+VALUES ("orders", 100.00),
+       ("merchandiese", 500.0),
+       ("services", 125.312);
+
+
+INSERT INTO expenses (expense_name, amount)
+VALUES ("wages", -240.00),
+       ("tax", -200.00),
+       ("repairs", -120.00)
+
+SELECT * FROM income
+UNION
+SELECT * FROM expenses;
+
+-------------- Unions does allow duplicates
+
+SELECT first_name, last_name FROM employees
+UNION
+SELECT first_name, last_name FROM customers;
+
+INSERT INTO customers (first_name, last_name)
+VALUES ("thuta", "sann updated")