A useful blog for all those who want to prepare for a SQL interview. That’s because, we are going to discuss over here, basic SQL interview questions and answers. Take a look at these popular SQL questions, with answers to them as well!
Basic SQL Interview Questions and Answers for Freshers:
What is DBMS? State its different types
A database happens to be a structured collection of data.
A Database Management System (DBMS) is nothing but a software application that facilitates an interaction with the user, database and application itself, for capturing and data analysis.
It permits a user to interact with the database. The database data can be altered, erased and retrieved and can be of any kind such as numbers, strings, images and so forth.
DBMS is basically divided into two types:
– Non-Relational Database Management System: E.g. Mongo. Concepts like relations, attributes and tuples do not exist here.
– Relational Database Management System: E.g. MySQL. Here, the data is stored in the form of relations (tables).
List the different types of joins in SQL?
The JOIN clause is put to use to combine rows from multiple tables, in view of a related column between them. It is utilized to merge two tables or data retrieval from it. Basically, there are 4 joins in SQL, as follows:
– Right Join
– Left Join
– Full Join
– Inner Join
What is a table and field in SQL?
A table is a collection of data in an organized manner, arranged as rows and columns. While, a field alludes to the number of columns within a table. For instance:
Field: Emp Id, Emp Name, Emp Designation
Consider this to be amongst the basic interview questions and answers for freshers, as far as SQL is concerned. Therefore, always be prepared with this one.
State the difference between MySQL and SQL
SQL or the Structured Query Language, is a standard language based on the English language. MySQL on the other hand, is a database management system. SQL forms the core of the relational database which is utilized for access to and managing a database. MySQL turns out to be an RDMS (Relational Database Management System) e.g. SQL Server, Informix and so on…
What do you understand by the term Primary key?
A Primary key is a column (or a group of columns) or a set of them, that uniquely distinguishes each row inside a table.
– Null values are not permitted
– A primary key helps to uniquely identify a single row within a table
E.g. In an Employee table, Emp_ID would be the primary key
Explain data integrity
Data Integrity characterizes the accuracy and in addition, the consistency of the data present in a database. It additionally characterizes integrity constraints for applying business rules on the data, at the time it is entered into an application or a database.
For now, we have come to the end of the list of basic SQL interview questions and answers for freshers. We will see some more later.
Till then, you can take a look at basic interview questions and answers for freshers in BPO, only on SayTooLoud.