Please let me know if UNION ALL and Natural Join does the
same operation and are same...
Answer Posted / vasanth
Hi All....!
Natural join is the same as an equi join on (emp.deptno =
dept.deptno).
Natural joins may cause problems if columns are added or
renamed. Also, no more than two tables can be joined using
this method. So, it is best to avoid natural joins as far
as possible.
If you will come to UNION ALL.
UNION ALL query allows you to combine the result sets of 2
or more "select" queries. It returns all rows (even if the
row exists in more than one of the "select" statements.
Each SQL statement within the UNION ALL query must have the
same number of fields in the result sets with similar data
types.
For Example :-
select field1, field2, . field_n
from tables
UNION ALL
select field1, field2, . field_n
from tables;
| Is This Answer Correct ? | 18 Yes | 3 No |
Post New Answer View All Answers
Can dml statements be used in pl/sql?
How we can update the view?
What is java sql connection?
What is left join in sql?
Is it possible to create the following trigger: before or after update trigger for each row?
What is latest version of sql?
what is cursor. write example of it. What are the attributes of cursor.
What is an inner join sql?
What is a variable in sql?
how to check myisam tables for errors? : Sql dba
How do we use distinct statement? What is its use?
What is primary key and foreign key?
How do I make sql search faster?
What is sql trigger example?
Explain what is a view?