Technical Interview Questions
ACID property is used to ensure that the data transactions are processed reliably in a database system. A single logical operation of a data is called transaction. ACID is an acronym for Atomicity, Consistency, Isolation, Durability. Atomicity: it requires that each transaction is all or nothing. It means if one part of the transaction fails, … Read more
SELECT TOP 1 salary FROM ( SELECT TOP 3 salary FROM employee_table ORDER BY salary DESC ) AS emp ORDER BY salary ASC; Certainly! To retrieve the third maximum salary from the employee_table, you can use the following SQL query: SELECT DISTINCT salary FROM employee_table ORDER BY salary DESC LIMIT 2, 1; Explanation: ORDER BY … Read more
SELECT * FROM Employees WHERE EmpName like ‘A%’ Certainly! To find the names of employees whose names start with ‘A’ in an SQL database, you can use the SELECT statement with the LIKE clause. Here’s an example query: SELECT employee_name FROM employees WHERE employee_name LIKE ‘A%’; In this query: SELECT employee_name specifies the column you … Read more
Constraints are the rules and regulations which are applied to the table column which enforces yours to store valid data and prevents users to store irrelevant data. There are two levels : column level constraint table level constraint In SQL, a constraint is a rule or condition that is enforced on data in a table. … Read more
The BETWEEN operator is used to display rows based on a range of values. The values can be numbers, text, and dates as well. BETWEEN operator gives us the count of all the values occurs between a particular range. The IN condition operator is used to check for values contained in a specific set of … Read more