SQL Join, Inner Join, Outer Join, Left join
Join == inner join, it selects records that have matching value in both tables.
Outer join equals to full join: it returns all the records when there is match in left and right table records.
Left join returns all the records from the left table and the matched records from the right table. if there is no match in right side, then we use default value of null.

浙公网安备 33010602011771号