SQL Interview Questions free PDF

In this tutorial, we shall go through the basic and yet most frequently asked SQL Interview Questions.

• SQL Interview Questions
• Q1 - What do you mean by Data, DataBase and DataBase Management Systems?
• Q2 - What is the difference between SQL and SQL server?
• Q3 - What is the difference between DBMS and RDBMS?
• Q4 - What is a key and what are different types of keys?
• Q5 - What is the basic difference between DELETE, DROP and TRUNCATE commands?
• Q6 - Which query is used to rename a column in a particular table?
• Q7 - What are the specifying attribute constraints and attribute defaults in SQL?
• Q8 - What is the built-in-function to count the total number of record in the table?
• Q9 - Which query is used to display the current date(today’s) date in the system?
• Q10 - What are set operations in SQL?
• Q11 - What is a join clause and what are the types of joins in SQL?
• Q12 - What do we need PL/SQL even though we haveSQL?
• Q13 - What is a cursor?
• Q14 - What are cursor attributes?
• Q15 - What do you mean by triggers?
• Q16 - What is normalization and what are different normal forms?
• Q17 - When do we call a table is in first normal form?
• Q18 - When do we call a table is in second normal form?
• Q19 - When do we call a table is in third normal form?
• Q20 - When do we calla table is in Boyce and Codd Normal Form (BCNF)?
• Q21 - When do we call a table is in Fourth Normal Form (4NF)?
• Q22 - Why do we need indexing?
• Q23 - What is a relationship and what are they?
• Q24 - What are all the different types of indexes?
• Q25 - What is a Stored Procedure?
• Q26 -  What is Data Integrity?
• Q27 - What are aggregate and scalar functions?
• Q28 - How do you create an empty table from an existing table?
• Q29 - How to select unique records from a table?
• Q30 - Which operator is used in the query for pattern matching?
• Q31 - What do you mean by  DDL, DML, and DCL in SQL?
• Q32 - Explain set operations in SQL?
• Q33 - What is Collation?
• Q34 - Explain the working of SQL Privileges?
• Q35 - What are Nested Triggers?
• Q36 - What is the difference between UNIQUE and PRIMARY KEY constraints?
• Q37 - What do you mean by SQL Injection?
• Q38 - Write an SQL Query to find the name of students whose name Start with ‘M’?
• Q39 - Write an SQL Query to display the current data?
• Q40 - What is the difference between the WHERE and HAVING clause?
• Q41 - Write a query to find a duplicate record in one field and also find the duplicate record with more than one field?
• Q42 - How do we use DISTINCT statement? What is its use?
• Q43 - What is the difference between nested subqueries and correlated nested subqueries?
• Q44 - How can you save all changes made by DML statements?
• Q45 - How can you undo the transactions that have not already been saved to the database?
• Q46 - Is NULL value same as blank space or zero?
• Q47 - What is the difference between IN and BETWEEN operator in SQL?
• Q48 - Do the views have data in the table?
• Q49 - What is the difference between GROUP BY and ORDER BY statements?
• Q50 - How will you find the name of the student with the third largest mark in a class?
• Q51 - What is the difference between primary key and unique constraints?
• Q52 - What are the desirable properties of transactions?
• Q53 - What are clustered and non-clustered Indexes?
• Q54 - When an explicit cursor needed?
• Q55 - What are the advantages of Views?
• Q56 - What is AutoIncrement?
• Q57 - What are the advantages and disadvantages of a Stored Procedure?
• Q58 - What is the difference between Rename and Alias?
• Q59 - What is the order of SQL SELECT?
• Q60 - What is the SQL CASE statement?