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Left Outer Join - Entire rows from left table but only matched rows from right table.
Right Outer Join - Entire rows from right table but only matched rows from left table.
As you might know why an outer join used for, when 1 of the joining table may not have referencing records but we have to get records from main table (master table in a master child relation).
So in a table we join table1 with table2 with having all records from table 1 but only existing referenced records from table2 we can use left outer join (table1 left outer join table2 on table1.column = table2.column)
And if we need to get all records from table2 and referencing records from table1 we can use right outer join in the same syntax. But when we are dealing with 2,3 tables, best practice is to use left outer join if possible.
If we join two tables like Table1 and Table2
SELECT * FROM Table1 A
LEFT JOIN Table2 B ON A.EmployeeID=B.EmployeeID
Above Query come with output matching both table column and remaining record of left table,that record didn't match with table colum ,left one table is(Table1 ).Similarly with right join