Database

A database is a collection of information that is organized so that it can be easily accessed, managed and updated. Before starting with the most popular...

A database is must need for any software development and which database to choose is one of the main requirement for software architecture. In...

Hi Programmers, In this article, we discuss most Popular Database Queries For an Interview. Do you want to apply at Google, Amazon, Microsoft, Facebook, Apple...

Suppose that a website contains two tables, the tableCustomers and the tableOrders. Write a SQL query to find all customers who never order anything. Table:...

Write a SQL query to delete all duplicate email entries in a table named,Person keeping only unique emails based on its smallestId. +----+------------------+ | Id | Email...

Given a Weather table, write a SQL query to find all dates' Ids with higher temperature compared to its previous (yesterday's) dates. +---------+------------+------------------+ | Id(INT) | Date(DATE) |...

The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name...

Given a table salary, such as the one below, that has m=male and f=female values. Swap all f and m values (i.e., change all f...

Table: Person +-------------+---------+ | Column Name | Type | +-------------+---------+ | PersonId | int | | FirstName |...