What is a join and explain different types of joins?
Answer Posted / kavita
Join are used to link then retrive data from same or
different database(both have atleast one common attribute).
Join are basically of two types:
1)Equi Join
2) Non equi join
Equi join are those in which we use "=" operator in
condition.They are further divided into
a)inner join:-In this only those rows are return which
satisfy the condition.
b)Outer join:In this all rows are return in which either one
table satisfy the condition
Outer Join are again classified into left join and right join.
2)Non Equi Join are those in which we use ">","<",">=","<="
operator for retriving tuples from two tables
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