DEHURTIGE:


1. 3. Generelt gælder dte at har vi N relationer, skal vi bruge N-1 betingelser for at undgå det cartetiske produkt.


2. 	SELECT COUNT(name) as antal 
    	FROM mytable
	WHERE name = "Mogens"
	GROUP BY name


3. 	SELECT * 
	FROM Signup 
	LIMIT 3

4. UPDATE Student SET sname = "Palle Gulvballe" WHERE sname = "Åge Brodtgaard"

5. 


CREATE TABLE Student (
sid INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
sname VARCHAR(80),
address VARCHAR(80)
) TYPE=InnoDB;


CREATE TABLE Course (
cid INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
cname VARCHAR(80),
teacher VARCHAR(80)
)TYPE=InnoDB;


CREATE TABLE Signup (
sid INT NOT NULL,
cid INT NOT NULL,
PRIMARY KEY (sid,cid),
FOREIGN KEY (sid) REFERENCES Student(sid),
FOREIGN KEY (cid) REFERENCES Course(cid)
)TYPE=InnoDB;