Here we come with DBMS questions for job interview which help you to prepare for the interview.
Overview of DBMS
A Database is a collection of related data organized in such a way that all data can be easily accessed, managed, and updated.
DBMS helps to reduce the anomalies found in a table.
A DBMS is software that allows the creation, definition, and manipulation of a database. DBMS is actually a tool used to perform any kind of operation on data in the database. Example: MySQL, Oracle, Sybase, etc.
- There are mainly 4 types of DATABASE MODEL
- Hierarchical Model.
- Network Model.
- Entity-Relationship Model.
- Relational Model.
- ENTITY:- An Entity is generally a real-world object which has it’s own characteristics and holds the relationships in a DBMS.
- ATTRIBUTE:- Attributes describe the characteristics or properties of an entity in a database table. An entity may contain more than one attribute.
- In DBMS there are basically three types of relationships-
- One to One relation.
- One to Many relations.
- Many to Many relations.
KEYS in DBMS
is an attribute or set of attributes that help you to identify a row(TUPLE) in a relation(table). They allow you to find the relation between two tables. Keys help you uniquely identify a row in a table by a combination of one or more columns in that table.
- There are mainly 7 different types of keys-
- Primary Key.
- Super Key.
- Candidate Key.
- Alternate Key.
- Foreign Key.
- Compound Key.
- Composite Key.
- Surrogate Key.
Database Normalization is a technique of organizing the data in the database. Normalization is a systematic approach of decomposing tables to eliminate data redundancy(repetition) and undesirable characteristics like Insertion, Update, and Deletion Anomalies.
There are few normalization forms such as-
- Structure Query Language(SQL) is a database query language used for storing and managing data in Relational DBMS.
DBMS questions for job interview help to grow your knowledge, go and practice it
DBMS quiz question:-
#1. _____ express the number of entities to which another entity can be associated via a relationship set.
#2. An entity in A is associated with at most one entity in B. An entity in B, however, can be associated with any number (zero or more) of entities in A.
#3. Data integrity constraints are used to:
#4. _____ is a special type of integrity constraint that relates two relations & maintains consistency across the relations.
#5. Drop Table cannot be used to drop a table referenced by a ___ constraint.
#6. We indicate roles in E-R diagrams by labeling the lines that connect ____ to _____
#7. For a weak entity set to be meaningful, it must be associated with another entity set, called the
#8. Weak entity set is represented as
#9. What term is used to refer to a specific record in your music database; for instance; information stored about a specific album?
#10. SELECT * FROM teaches WHERE Sec_id = 'CS-101'; Which of the following Id is selected for the following query?
#11. The relation changes can be got back using ____ command
#12. The total participation by entities is represented in E-R diagram as
#13. In E-R diagram generalization is represented by
#14. A primary key is combined with a foreign key creates
#15. The entity set person is classified as student and employee. This process is called
#16. If an entity set is a lower-level entity set in more than one ISA relationship, then the entity set has
#17. A _____ constraint requires that an entity belong to no more than one lower-level entity set.
#18. Which of the following is another name for a weak entity?
#19. In an E-R, Y is the dominant entity and X is a subordinate entity. Then which of the following is incorrect?
#20. E-R modelling technique is a:
#21. The number of entities to which another entity can be associated via a relationship set is expressed as:
#22. Every weak entity set can be converted to a strong entity set by:
#23. Relations produced from an E-R model will always be in :
#24. Drop Table cannot be used to drop a table referenced by a ___ constraint.
#25. The entity relationship set is represent by in E-R diagram as
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