What are the differences between UNION and JOINS?
Answers were Sorted based on User's Feedback
Answer / saravakumar
A join selects columns from 2 or more tables. A union
selects rows.
Is This Answer Correct ? | 7 Yes | 0 No |
Answer / sree
UNION:The SQL UNION operator combines two or more SELECT
statements.
JOINS:SQL joins are used to query data from two or more
tables, based on a relationship between certain columns in
these tables.
Is This Answer Correct ? | 4 Yes | 0 No |
Answer / nikhila reddy
UNION:the both tables should have same structure and datatype.
the column name will taken as first table ones it wont bother abt other tables.
example:
emp table as
eid ename esal
1 a 10k
2 b 20k
dept table as
deptid deptname deptsal
11 aa 20k
12 bb 50k
select * from emp
union
select * from dept
empid empname empsal
1 a 10k
2 b 20k
11 aa 20k
12 bb 50k
now u can observe col name taking alias of first table.
no need of relation between a tables.
it will remove duplicate records.
joins:it will join only required fields from different tables.
no need of same structure for tables..
it should have relation between a tables.
Is This Answer Correct ? | 0 Yes | 0 No |
I have cleared sbi clerk examination. I am Bachelor in computer application (BCA) graduate. so which type of question related bca in sbi clerk interviews. pls answers me at sejalvaghela@yahoo.co.in.. and also tell me which type of question asked in sbi clerk interview.
Which feature in sql server 2008 has surprised you? You can name just one. : sql server database administration
What is the distinction amongst delete and truncate?
Differentiate between truncate vs delete in mssql?
Why we need sql server?
What is bit datatype and what's the information that can be stored inside a bit column?
What is an inner join?
What about UPDATESTATISTICS ?
Explain collation?
Do you know what are the ways available in sql server to execute sql statements?
Can we drop user if user mapped to any logins
How to compose an inquiry to demonstrate the points of interest of an understudy from students table whose name begins with k?