what is the difference between joins and set operators.i am
always confusing with two,can u pls kindly help me .
Answers were Sorted based on User's Feedback
Answer / amretha
For set operators the columns in the tables must be the same.Where as for Joins if one column is same its enough to join two or more tables.
Is This Answer Correct ? | 19 Yes | 2 No |
Answer / jyoti
Set - Comparison is to be performed on Tables.
Join- Comparison is to performed on rows of tables.
Is This Answer Correct ? | 9 Yes | 3 No |
joins project the data from more than one table vertically
based on common cloumns among the tables.
in case of set operators, its combine(merge) data horizantally, programer have to manage the correct logic and sence in the data. set operators uses for data presentation.
Is This Answer Correct ? | 5 Yes | 6 No |
Answer / mahesh
suppose if we have joined two tables display the both table column names whatever we are giving and incase if we are use set operators columns not displyaed both tables.only first select query columns only displayed.
Is This Answer Correct ? | 1 Yes | 5 No |
Does oracle charge for java?
23. Display the client name for all clients who have placed an order where any order line has more than 3 items. Do not use a table join anywhere in your query.
Describe Referential Integrity ?
What are the advantages of Views ?
How to install oracle odbc drivers?
Difference between inner join vs where ?
What is a directory object?
what are archived logs?
What is blob datatype?
what is the difference between authorization and authentication?
What is the difference between a primary key & a unique key?
What is the effect of setting the value "all_rows" for optimizer_goal parameter of the alter session command? What are the factors that affect optimizer in choosing an optimization approach?