Explain an outer join?

suppose i have two tables emp(emp id, sal, isn) and stud(stud id, isn,total_mark).

now i join the two tables using outer join.

if i take sal from emp and total_mark from stud ,then after the join

all the rows from the stud table will be there where as only selected rows from emp as per the condition will be there.

3 types.

Left outer Join----left table unmatched valyes are included.
Right Outer Join---right table unmatched values are included.
Full outer Join----Both table unmatched values are selected.

  1 User has rated as useful.

  

Login to rate this answer.

Outer Join is a type of join where the matching rows from the given tables are selected for sure and it follows following criteria to select unmatched rows.
1. LEFT OUTER JOIN it will give All Matching + Unmatching rows of Left table in SQL.
2. RIGHT OUTER JOIN it will give All Matching + Unmatching rows of Right table in SQL.
3. FULL OUTER JOIN it will give All Matching + Unmatching rows of Both tables in SQL.

Hope this helps.