levo spoljno spajanje(A type of outer join in which all rows from the left-most table in the JOIN clause are included. When rows in the left table are not matched by rows in the right table, all result set columns that come from the right table are assigned a value of NULL)
spoljno spajanje(A join that includes all the rows from the joined tables that meet the search conditions, even rows from one table for which there is no matching row in the other join table)
desno spoljno spajanje(An outer join in which all the records from the right side of the RIGHT JOIN operation in the query's SQL statement are added to the query's results, even if there are no matching values in the joined field from the table on the left)