To select some particular columns which of the following command is used mcq
A database is an organized and systematic collection of data, which is stored electronically on a computer. We can add, update, delete or retrieve data from the database. A database consists of sets of tables or objects which contain records and fields. A row in the database represents a single entry and columns define the attributes which define a particular aspect or property of the table. Show
Problems with File System
Advantages of DBMS
As far as placements are concerned, companies need all-rounder candidates. Every software engineer should have basic knowledge of databases because no matter which technical position you are in, you may have to interact with the database. So, you will definitely require some DBMS knowledge or skills to get a placement. Studying DBMS interview questions can help you in clearing the technical rounds of the interview process. DBMS Interview Questions – Top 20 MCQs1. What is the full form of DDL?
Answer: DDL stands for Data definition language and is used to define the structure of the database. 2. Which of the following is not a command of DML?
Answer: GRANT. GRANT is a data control command and is used to provide access to the database to an user. 3. Which of the following is not a command of DDL?
Answer: SELECT. SELECT is a data manipulation command and is used to retrieve data from the database. 4. DROP command is used for?
Answer. Deleting one or more rows from a table. 5. Which property of the DBMS is responsible to protect the data of a transaction during system failure?
Answer: Durability. The property of durability protects the data of a transaction during system failure. 6. Which normalization form is based on the transitive dependency?
Answer: 3 BF. The 3NF is based on the transitive dependency. 7. Rows of a relation is known as?
Answer: Tuple. Rows of a relation are known as tuple. 8. What is the highest level of data abstraction?
Answer: View. View is the highest level. It simplifies the view of the database by providing multiple views of the database.
Answer: Internal. Internal level defines how the data is actually stored, it defines data-structures to store data and access methods used by the database. 10. Rectangles in ER diagram represents?
Answer: Entry sets. The rectangles in the ER diagram are used to represent entity sets. 11. Which of the following allows you to uniquely identify a tuple?
Answer: Super key. Super Key helps us to uniquely identify a tuple in a relation. 12. What is the full form of NFTS?
Answer: New Technology File System. 13. Which command is used to find the number of values in a column?
Answer: COUNT. COUNT command is used to find the number of values in a column. 14. Which statement is executed automatically by the system as a side effect of the modification of the database?
Answer: Trigger. Trigger is a stored procedure in the database which is automatically executed whenever an event in the database occurs. 15. An index is clustered, if
Answer: The data records of the file are organized in the same order as the data entries of the index. 16. Primary can be ?
Answer: NOT NULL. Primary key cannot be NULL as it the key which is used to uniquely identify each row in a table. 17. Which Command is used to select some particular columns?
Answer: PROJECTION. PROJECTION is used to select some particular columns. 18. What is the Maximum children of a B- tree of order N?
Answer: N. B- tree is a self balancing tree which can have a maximum of N children. 19. The number of tuples of a relation is known as?
Answer: Cardinality. Cardinality is the number of tuples of a relation. 20. Which of the following database objects does not physically exist?
Answer: View. View is just a concept and it does not exist physically. We tried to discuss DBMS Interview Questions in this article. We hope this article gives you a better understanding of the type of DBMS Interview Questions. Prepbytes also provides a good collection of Foundation Courses that can help you enhance your coding skills. Want to make sure you ace the interview in one go? Join our Placement Program that will help you get prepared and land your dream job at MNCs. Mentors of Prepbytes are highly experienced and can provide you with basic, in-depth subject knowledge for better understanding. Which of the following commands is used to view the columns of a table using SQL code?So desc or describe command shows the structure of table which include name of the column, data-type of column and the nullability which means, that column can contain null values or not.
Which command is used to the list of database Mcq?Explanation: DDL commands are used to define the structure of the database, table, schemas, etc.
Which one of these is used with SELECT clause to fetch all columns from a table Mcq?Explanation: “SELECT” clause is used to show all rows or columns.
Which of the following commands will you use to UPDATE values in a table Mcq?The UPDATE command is used to update existing rows in a table. The ALTER is used to add, delete, or modify columns in an existing table. and also used to add and drop various constraints on an existing table.
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