Database Interview Questions and Answers
Question - 71 : - What do you mean by SQL injection?
Answer - 71 : -
Black-hat hackers use the SQL injection technique that hacks the data from databases or tables.
Question - 72 : - Explain about trigger in SQL
Answer - 72 : -
Trigger in database refers to the stored program. This automatically responds to the operations of DML by inserting, deleting, or updating.
Question - 73 : - How can you add several rows in Structured Query Language?
Answer - 73 : -
We can use the following syntax to add several rows in Structured Query Language:
INSERT INTO table_name (column1, column2,column3...)
VALUES
(value1, value2, value3…..),
(value1, value2, value3….),
...
(value1, value2, value3);
We will add the keywords ‘INSERT INTO’ and enter the table’s name to add values. It will be followed by column lists and adding values for them. Then we will type the keyword ‘VALUE’ and provide the list of values.
Question - 74 : - Can you get the nth highest salary in Structured Query Language?
Answer - 74 : -
Here’s how we can get the nth highest salary in SQL SERVER by utilizing the TOP keyword:
SELECT TOP 1 salary FROM ( SELECT DISTINCT TOP N salary FROM #Employee ORDER BY salary DESC ) AS temp ORDER BY salary
To get the nth highest salary in MYSQL, we can use the LIMIT keyword. Here’s the solution:
SELECT salary FROM Employee ORDER BY salary DESC LIMIT N-1, 1
Question - 75 : - How can you insert a new column in the Structured Query Language?
Answer - 75 : -
By using alter command, we can insert a new column in the Structured Query Language:
ALTER TABLE employees ADD COLUMN contact INT(10);
Question - 76 : - What programming languages besides SQL must you know to crack the database interview questions?
Answer - 76 : -
To crack a database interview, you must be skilled with programming languages such as R and Python, besides SQL.
Question - 77 : - What advanced SQL questions must you prepare for technical interviews?
Answer - 77 : -
You must know the concepts of SQL like a key, stored procedures, parameters, commands, and functions. Besides, you must be adept at writing queries to organize and restore data from the database to prepare for technical interviews.
Question - 78 : - How to prepare for the basic database interview questions?
Answer - 78 : -
You can easily prepare for the basic database interview questions by looking at this list. Alternatively, you can enroll yourself in a reliable tech interview prep course.
Question - 79 : - What are the four contents of a database?
Answer - 79 : -
The four database contents are data, procedure, hardware, software, and database access language.
Question - 80 : - What are the six database objects?
Answer - 80 : -
The six objects in a database are relationships, tables, queries, macros, forms, and reports.