/*
	Information about pets is kept in two separate tables:
	TABLE dogs
	  id INTEGER NOT NULL PRIMARY KEY,
	  name VARCHAR(50) NOT NULL

	TABLE cats
		  id INTEGER NOT NULL PRIMARY KEY,
		  name VARCHAR(50) NOT NULL

	Write a query that select all distinct pet names.
*/




-- create a table
CREATE TABLE dogs (
         id INTEGER NOT NULL PRIMARY KEY,
		  name VARCHAR(50) NOT NULL,
          age  INTEGER NOT NULL
);

CREATE TABLE cats (
         id INTEGER NOT NULL PRIMARY KEY,
		  name VARCHAR(50) NOT NULL,
         age  INTEGER NOT NULL
);


-- insert some values
INSERT INTO dogs VALUES (1, 'Ryan', 20);
INSERT INTO dogs VALUES (2, 'Joanna', 30);
INSERT INTO dogs VALUES (3, 'frr', 45);
INSERT INTO dogs VALUES (4, 'reg', 10);

INSERT INTO cats VALUES (1, 'Ryan', 20);
INSERT INTO cats VALUES (2, 'Joanna', 30);
INSERT INTO cats VALUES (3, 'Joanna', 45);
INSERT INTO cats VALUES (4, 'Mar', 10);

-- fetch some values
--SELECT * FROM  cats ;

--distinc names
--SELECT distinct Name FROM  cats ;

--select names, age from both 

-- select a.name as dog_name, b.name as cat_name from dogs a cross join cats b ;

select distinct name from 
(
 select name from dogs
 union all
 select name from cats
) ;