Query

[2time]

am tabelele urmatoare

students(id int not null, name varchar(10), year int, primary key (id asc))

classes(id int not null, name varchar(15), class_room_number int, primary key (id asc))

class_rooms(number int not null, primary key (number asc))

students

4 | student4 | 2

5 | student5 | 3

classes:

1 | mathematics | 345

2 | biology | 78

4 | english | 112

class_rooms:

345

78

112

si trebe sa extrag din aceste tabele cu un query ca sa imi iasa asa rezultatul

student1 | 5 | 345 | mathematics

student2 | 5 | 345 | mathematics

student3 | 5 | 345 | mathematics

am incercat cu formula asta :"select name , year from students where year='5' union select name,class_room_number from classes where class_room_number='345'" dar nu mi le aseaza asa din cauza ca am name in ambele tabele ns cum sa le separ ma poate ajuta careva ?

[Robert1995]

Hai ca incerc eu asa "pe sec" netestat .

SELECT s.name, s.id, crm.class_room_number, crm.name FROM students s LEFT JOIN classes ON class_room_number crm = 345