The abbreviation SQL, pronounced “ess-que-el” or “see-kwell” is quite a trending skill to learn. In this post we will discuss
SQL Interview Questions asked in 2023 interviews..SQL is not a programming language, at least not exactly. It is a “query language”.
Now, one Question arises, What does a query language mean?
A query language is a computer programming language that retrieves information from a database. So, SQL is a query language that is used to communicate with the database. It is used to update or retrieve data from a database.
Query languages are aimed to manipulate data (usually create, read, update and delete it) whereas high-level programming languages are used by humans to instruct a computer which actions it has to do in order to solve some problem.
🚀 SQL (structured query language) is a language for specifying the organisation of databases (collections of records).
Databases organised with SQL are called relational, because SQL provides the ability to query a database for information that falls in a given relation.
🚀 SQL is used to maintain the relational database and perform many different data manipulation operations on the data. SQL was initially invented in 1970. It is a database language used for database creation, deletion, fetching and modifying rows, etc. sometimes, it is pronounced as 'sequel.' We can also use it to handle organised data composed of entities (variables) and relations between different entities of the data.
🚀 It is true that SQL is a language but does not actually support the programming language. It is a common language that doesn't have a loop, conditional statements, and logical operations. It cannot be used for anything other than data manipulation. It is a command language to perform database operations. The primary purpose of SQL is to retrieve, manipulate, update, delete, and perform complex operations like joins on the data present in the database.
SQL is responsible for maintaining the relational data and the data structures present in the database. Some of the common usages are given below:
🚀 It helps in executing queries against a database
🚀 It helps to retrieve data from a database
🚀 It helps to inserts records in a database
🚀 It helps to updates records in a database
🚀 It helps to delete records from a database
🚀 It helps to create new databases
🚀 It helps to create new tables in a database
🚀 It helps to create views in a database
🚀 It helps to perform complex operations on the database.
The need of SQL does not end here, we can perform many other database-related tasks with SQL. We will learn about all of them in detail in form of interview questions and answers.
SQL is used to view, manage and access that data, it is well suited for Data Manipulation. It gives the users an easier time to test and manipulate the data. Furthermore, data stored in SQL is dynamic. So, you can go forward and manipulate the data at any instance of time.
SQL programming skills are highly desirable and required in the market, as there is a massive use of Database Management Systems (DBMS) in almost every software application. In order to get a job, candidates need to crack the interview in which they are asked various SQL interview questions.
Since data analysts work with data daily, SQL is a required skill for them. It is easy to learn and understand. SQL helps data analysts gain access directly to large sets of data in the database without having to duplicate data into other applications.
This page will help you to brush up on your SQL skills, regain your confidence and be job-ready!
Here, you will find a collection of real-world SQL Interview questions asked in companies like Google, Oracle, Amazon, and Microsoft, etc. Each question comes with a perfectly written answer inline, saving your interview preparation time.
It also covers practice problems to help you understand the basic concepts of SQL. You are provided with the easiest way for solving queries that are usually asked during the interviews.
So, let’s begin with the SQL Interview Questions.
A JOIN clause is used to merge rows from
two or more tables, based on a linked
column between them.
The UPDATE statement is used to change
the contents of a table's existing records.
SQL Injection is a type of code injection
that has the potential to completely ruin
A view is a virtual table in SQL that is created
from the result set of a SQL operation.
A SQL trigger is a database object which
fires when an event occurs in a database.
Aggregate function adds together numerous
numbers and returns a single result.
SQL commands are instructions.
It's used to
send and receive data from the database.
Inserting one or more rows into a database
table with specified table column values is
done with the insert command.
The INNER JOIN keyword selects records
from both tables that have matching values
When a SQL statement is performed, a
cursor is a temporary work area established
in system memory.
A stored procedure is a piece of prepared
SQL code that you can save and reuse over
A FOREIGN KEY is a field in one table that
relates to another table's PRIMARY KEY.
A wildcard character is one that can be
substituted for one or more characters in
The nature of the data that can be recorded
in a database table is represented by data
Operators are SQL reserved words
and characters that are used with a WHERE
clause in a SQL query.
Null values are also beneficial for keeping
the datatype consistent across the column.
Datetime (time is also linked with date) is
used in many contexts instead of date.