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 Unique key constraint uniquely identified e...
Date, c.Name, r.Name AS ReferredByName FROM Invoices i JOIN Customers c ON i.CustomerId = c.Id LEFT JOIN Customers r ON c.ReferredBy = r.Id ORDER BY i.BillingDate; This question simply tests the candidate’s ability take a plain-English requirement and write a corresponding SQL query...
SQL (Structured Query Language) Interview Questions And AnswersSharpen your SQL interview expertise with our handpicked 172 questions. Each question is crafted to challenge your understanding and proficiency in SQL. Suitable for all skill levels, these questions are essential for effective preparation. ...
and the outer query is known as the main query in the Database. The implementation of subqueries is always done first, and the outcome of the following is always passed on to the main query.
DQL –Data Query Language– performs the query operations on the data within schema objects; DML –Data Manipulation Language– manipulate the data present in the database; DCL –Data Control Language– manages the database system’s rights, permissions, and other controls. ...
article i will try to explain most important PL/SQL Interview Questions that may ask in interview.PL/SQL is the Procedural Language Structured Query Language which will use to add the business logic. In this article I will try to give the brief description about different PL/SQL interview ...
big query here ) SELECT * FROM YourTable1 WHERE ID IN (SELECT ID FROM YourBigCTE) UNION SELECT * FROM YourTable2 WHERE ID IN (SELECT ID FROM YourBigCTE) Scope is next immediate select command. Can be used multiple times within the same CTE command, even recursively, and will last for...
SQL, 全称是Structured Query Language(结构化查询语言)。 SQL与database(数据库)紧密相连,数据库的主要作用就是用来存储大量的数据,如果我们想要操作数据库中的数据,那么就主要靠SQL啦,例如 增改删查 等等。 之前见到过一个很好的比喻,感觉很形象:如果把数据库比作盘子,那数据就是盘子里的菜,SQL则是你的筷子。
在2024 年的面试中,SQL 主要集中在电话面试阶段(phone interview),而在现场面试(onsite interview)中,SQL 的考察大幅减少,取而代之的是Python。这显示出大厂越来越注重候选人实际的数据处理能力,而不是简单的数据提取能力。这些公司不仅仅包括谷歌和 Meta,还包括像 Roblox、DoorDash 这样的新兴独角兽。 因此,掌握了...
4. How to find the query running on a given SPID? 5. What is XACT_ABORT ON? 6. Can we use two CTE’s in a single select query? 7. What are the different join operators in SQL Server? 8. Can we use a table variable inside a nested stored procedure if the table variable created...