SQL or Structured Query Language, is a programming language designed for managing and querying relational databases. It allows you to create, read, update, and delete data in databases, making it essential for working with data-driven systems. It forms the backbone of most modern applications, ma...
1:: What is SQL (Structured Query Language)? SQL is an English like language consisting of commands to store, retrieve, maintain & regulate access to your database. Read More 2:: What is the SQL*Plus? SQL*Plus is an application that recognizes & executes SQL commands & specialized SQL*...
When we execute a query and use theWHEREkeyword on a column that does not have an index, then the SQL Server has to do a full-table scan and check every row to find matches. This is a bad practice because it can be unpredictable in terms of execution time. Therefore this process may...
Example: SQL Server. 3. What is SQL? SQL stands for Structured Query Language , and it is used to communicate with the Database. This is a standard language used to perform tasks such as retrieval, updation, insertion and deletion of data from a database. 7. What is a unique key? A...
SQL Interview Question 面试的时候发现会问一些SQL的基本问题,在此总结一下。 ProgramInterview/SQL这个网站上的问题还比较全。 1. Join type INNER JOIN: Returns all rows when there is at least one match in BOTH tables LEFT JOIN: Return all rows from the left table, and the matched rows from ...
Eventually, in an outer query, apply aWHEREfilter and aCOUNT()function on the result of the subquery. Solution of SQL Interview Question #3 Solution: SELECT department_name, AVG(salaries.salary) AS avg_salariesFROM employeesJOIN salariesON employees.employee_id = salaries.employee_idGROUP BY dep...
SQL Server books online has enough information on this topic and there is a good white paper available on Microsoft site. 12. Explain the architecture of SQL Server This is a very important question and you better be able to answer it if consider yourself a DBA. SQL Server books online is...
Question #2: Trips and Users (MySQL) “Thecancellation rateis computed by dividing the number of canceled (by client or driver) requests with unbanned users by the total number of requests with unbanned users on that day. Write a SQL query to find thecancellation rateof requests with unbanned...
1 What is SQL Profiler? 1 What command using Query Analyzer will give you the version of SQL server and operating system? 1 What does it mean to have QUOTED_IDENTIFIER ON? What are the implications of having it OFF? 1 What is the STUFF function and how does it differ from the RE...
In my previous articles I have explained theSQL interview questions ,BI Interview questionswhich will give the best idea about the question that may ask in interview. In this article i will try to explain most important PL/SQL Interview Questions that may ask in interview.PL/SQL is the Proced...