200+ sql interview questions

SQL [Structured Query Language] PLACEMENT PREPARATION [EXCLUSIVE CONTENT]
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No Need of 200+ sql interview QUESTIONS These Top 30 are enough to Understand the Sql Concepts :-

What is SQL?
What is Database ?
What are the differences between
SQL and PL/SQL?
What is the difference between
BETWEEN and IN operators in
SQL?
What is the use of LIKE operator?
What is the use of ‘WHERE’
Clause?
What is the use of ‘Having’
Clause?
What are SQL Commands?
Explain types of SQL Commands
What are normalization and
denormalization and why do we
need them?
What are Nested Queries in SQL?
What are different types of
Normalization?
What is Stored Procedures in SQL
?
What are different types of case
manipulation functions available in
SQL.
What is the difference between
CHAR and VARCHAR2 datatype
in SQL?
What is the use of CREATE,
INSERT INTO, UPDATE and
DELETE Clauses?
What is the use of ADD, DROP
and MODIFY Commands?
What are VIEWS in SQL?
What are JOINS in SQL?
What is the use of GROUP BY
Clause?
What are Aggregate Functions?
What is Cursor in SQL ?
What is the difference between
Implicit and Explicit Cursor?
What is the difference between
VIEW and CURSOR in SQL?
What are the advantages of
PL/SQL functions?
Explain BETWEEN and IN
Clause.
What is the difference between
DROP and TRUNCATE?
What are Constraints in SQL?
What is a TRIGGER?
What is the use of LIMIT and
OFFSET in SQL?
What are different types of
operators present in SQL?

What is SQL?
Structured Query Language is a computer language that we use to interact with a
relational database.SQL is a tool for organizing, managing, and retrieving archived
data from a computer database. The original name was given by IBM as Structured
English Query Language, abbreviated by the acronym SEQUEL. When data needs
to be retrieved from a database, SQL is used to make the request. The DBMS
processes the SQL query retrieves the requested data and returns it to us. Rather,
SQL statements describe how a collection of data should be organized or what data
should be extracted or added to the database.
In common usage, SQL encompasses DDL and DML commands for create, updates,
modified or other operations on database structure.

SQL uses:

Data definition: It is used to define the structure and organization of the
stored data and relationships among the stored data items.
Data retrieval: SQL can also be used for data retrieval.
Data manipulation: If the user wants to add new data, remove data, or modifying in
existing data then SQL provides this facility also.
Access control: SQL can be used to restrict a user’s ability to retrieve, add, and
modify data, protecting stored data against unauthorized access.
Data sharing: SQL is used to coordinate data sharing by concurrent users, ensuring
that changes made by one user do not inadvertently wipe out changes made at
nearly the same time by another user.
SQL also differs from other computer languages because it describes what the
user wants the computer to do rather than how the computer should do it. (In more
technical terms, SQL is a declarative or descriptive language rather than a
procedural one.) SQL contains no IF statement for testing conditions, and no GOTO,
DO, or FOR statements for program flow control. Rather, SQL statements describe
how a collection of data is to be organized, or what data is to be retrieved or added
to the database. The sequence of steps to do those tasks is left for the DBMS to
determine.

Features of SQL:

SQL may be utilized by quite a number of users, which include people with very
little programming experience.
SQL is a Non-procedural language.
pg. 3 | HIMANSHU KUMAR(LINKEDIN)
We can without difficulty create and replace databases in SQL. It isn’t a timeconsuming process.
SQL is primarily based totally on ANSI standards.
SQL does now no longer have a continuation individual.
SQL is entered into SQL buffer on one or extra lines.
SQL makes use of a termination individual to execute instructions immediately.
It makes use of features to carry out a few formatting.
It uses functions to perform some formatting.

Rules For SQL :

A ‘;’ is used to end SQL statements.
Statements may be split across lines but keywords may not.
Identifiers, operator names, literals are separated by one or more spaces or other
delimiters.
A comma(,) separates parameters without a clause.
A space separates a clause.
Reserved words can not be used as identifiers unless enclosed with double quotes.
Identifiers can contain up to 30 characters.
Identifiers must start with an alphabetic character.
Characters and date literals must be enclosed within single quotes.
Numeric literals can be represented by simple values.
Comments may be enclosed between /* and */ symbols and maybe multi-line.