Database Management & SQL – Previous Year Questions
31 questions from past HTET PGT Computer Science papers, each with the correct answer. Open any question for its explanation.
- In SQL .......... is treated as a virtual table that is derived from other tables.
- The .......... states that no primary key value can be NULL.
- Which operation is used to change the values of one or more attributes in a tuple (or tuples) of some relation R?
- .......... are complete select-from-where blocks with in another SQL query.
- The select operation is used to choose a subset of tuples from a relation that satisfies a .............. .
- To get information from users you use ........... .
- This command is used to modify attribute values of one or more selected tuples :
- Degree of relationship type is the number of participating .............. .
- The query that is used to summarize the data from various tables is called as :
- In database ........... type of field is used to insert various objects mode in other Windows applications into table.
- A collection of concepts that can be used to describe the structure of database and provides the necessary means to achieve this abstraction :
- A field that gives each record a unique identity is called as :
- The capacity to change the conceptual schema without having to change the external schemas or additional programs is called as ............... .
- In SQL terminology a ................ is a single table that is derived from other tables.
- SQL command used to add a new column in an existing table is :
- In context of deadlock prevention in DBMS, wait-die and wound-wait schemes are ........ techniques.
- In context of databases consider set operations on relation R and S, and select a true statement :
- In context of 2-phase locking protocol in DBMS, a transaction issues lock requests in ......... phase and unlock requests in ........ phase.
- Choose the SQL commands to perform following operations on a relation R : I : Retain Relation R in database, but delete all tuples in R. II : Delete all information about R in Database.
- If the following functional dependencies holds on a selection R : A → B, A → C, BC → D, C → F, B → E, then which of the following dependency does not hold on R ?
- The ........... of weak entity set distinguishes among all those entities in the weak entity set that depends upon one particular strong entity.
- A function that has no partial functional dependencies is in …….. form.
- Which of the following is not a valid aggregate function ?
- SQL Views are also known as :
- If one attribute is determinant of second, which in turn is determinant of third, then the relation cannot be :
- Which of the following provides the ability to query information from the database and insert tuples into, delete tuples from, and modify tuples in the database ?
- Which of the following is true about the HAVING clause ?
- Which of the following is generally used for performing tasks like creating the structure of the relations, deleting relation ?
- Which of the following is not a DDL command ?
- The command center of MS-Access file that appears when you create or open the MS-Access database file, is called :