Advanced
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ABOUT SQL

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 2022 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.
If you are a beginner, you should consider learning SQL as it is much easier than programming languages like Java, JavaScript, C++ etc.


🚀 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.


Usage of SQL

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.

Why Sql In Interview?

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.

How Does This Page Help You?


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.

Most Common SQL Interview Questions


SQL Join

A JOIN clause is used to merge rows from
two or more tables, based on a linked
column between them.

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SQL CREATE TABLE

In SQL, the CREATE TABLE statement is used
to make a table.

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SQL Queries

We use Queries to retrieve meaningful
and relevant information from databases.

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Update Query in SQL

The UPDATE statement is used to change
the contents of a table's existing records.

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SQL Group By

The GROUP BY command creates
summary rows from rows with same values.

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SQL Injection

SQL Injection is a type of code injection
that has the potential to completely ruin
your database.

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SQL View

A view is a virtual table in SQL that is created
from the result set of a SQL operation.

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Triggers in SQL

A SQL trigger is a database object which
fires when an event occurs in a database.

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Constraints in SQL

SQL constraints are used to specify rules
for data in a table.

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SQL Aggregate Functions

Aggregate function adds together numerous
numbers and returns a single result.

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SQL Commands

SQL commands are instructions. It's used to
send and receive data from the database.

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SQL Index

A SQL Index is a quick lookup table for
locating records that are often searched.

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Insert Query in SQL

Inserting one or more rows into a database
table with specified table column values is
done with the insert command.

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SQL Inner Join

The INNER JOIN keyword selects records
from both tables that have matching values

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Cursor in SQL

When a SQL statement is performed, a
cursor is a temporary work area established
in system memory.

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Stored Procedure in SQL

A stored procedure is a piece of prepared
SQL code that you can save and reuse over
and over.

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Foreign Key in SQL

A FOREIGN KEY is a field in one table that
relates to another table's PRIMARY KEY.

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SQL Wildcards

A wildcard character is one that can be
substituted for one or more characters in
a string.

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SQL Data Types

The nature of the data that can be recorded
in a database table is represented by data
types.

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SQL Operators

Operators are SQL reserved words
and characters that are used with a WHERE
clause in a SQL query.

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SQL Transactions

A transaction is a logical unit of work
performed on a database.

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SQL NULL Functions

Null values are also beneficial for keeping
the datatype consistent across the column.

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SQL Keywords

SQL Keyword reference is provoided in
this page.With detailed description.

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SQL Date Functions

Datetime (time is also linked with date) is
used in many contexts instead of date.

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