SQLOS is thin layer which allows the communication between the SQL server database engine and Operating system This technique is only applicable in few scenarios. SQL > delete from emp where empno,empname,salary) in ( select max(empno),empname,salary from emp group by empname,salary ) Since both will give unique records when order by rowid. Here you can use both rank ( ) and dens_rank() SQL > delete from emp where rowid in (select rid from (select rowid rid, dense_rank() over(partition by empno order by rowid) rn from emp ) where rn > 1 ) This is another efficient way to delete duplicates SQL > delete from emp where rowid in (select rid from ( select rowid rid, row_number() over(partition by empno order by empno) rn from emp )where rn > 1) SQL > delete from emp e1 where rowid not in (select max (rowid) from emp e2 where e1.empno = e2.empno ) The columns which identify the duplicates. This technique can be applied to almost scenarios. SQL > delete from emp where rowid not in (select max (rowid) from emp group by empno) Here is the best and top SQL interview questions and answers.
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Our trainers are having more experience in working as a developer, designers, and debuggers in top companies. Besant Technologies provides the best SQL training in Chennai. SQL is a domain language used for managing and maintaining data which are done in a database system. In this post, you will get the most important and top SQL Interview Questions and Answers, which will be very helpful and useful to those who are preparing for jobs. The SQL questions are for intermediate to somewhat advanced SQL professionals, but even if you are just a beginner or fresher you should be able to understand the SQL answers and explanations here we give. These SQL questions and answers are suitable for both freshers and experienced professionals at any level.
Here is the list of most frequently asked SQL Interview Questions and Answers in technical interviews. These are top SQL interview questions and answers, prepared by our institute experienced trainers. We provide the SQL online training also for all students around the world through the GangBoard medium. SQL is the leading important course in the present situation because more job openings and the high salary pay for this SQL and more related jobs. If you want to learn Practical SQL Training then please go through this SQL Training in Chennaiīesant Technologies supports the students by providing SQL interview questions and answers for the job placements and job purposes.
Stay tuned we will update New SQL Interview questions with Answers Frequently. This SQL interview questions and answers are prepared by SQL Professionals based on MNC Companies expectation. We hope these SQL interview questions and answers are useful and will help you to get the best job in the networking industry. List of frequently asked SQL Interview Questions with answers by Besant Technologies. SQL Interview Questions and Answers for beginners and experts.