Explanation:This query joins the customers and orders tables on customer_id. It groups by customer_id and customer_name, then counts the number of orders for each customer. The HAVING clause filters the results to show customers with more than 5 orders. 12. Aggregate Functions with GROUP BY ...
SQL Job Interview Questions and Answers 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 &...
Using the NOLOCK query optimiser hint is generally considered good practice in order to improve concurrency on a busy system. When the NOLOCK hint is included in a SELECT statement, no locks are taken when data is read. The result is a Dirty Read, which means that another process could be...
But some general issues that you could talk about would be: No indexes, table scans, missing or out of date statistics, blocking, excess recompilations of stored procedures, procedures and triggers without SET NOCOUNT ON, poorly written query with unnecessarily complicated joins, too much ...
SQL Joins Interview Questions SQL Server Interview Questions PostgreSQL Interview Questions Interview Query Resource:Top 25+ Data Science SQL Interview Questions by Interview Query This interview guide will cover SQL interview questions you need to prepare as a data scientist. The guide divided into thre...
A database cursor can be thought of as apointer to a specific row within a query result. The pointer can be moved from one row to the next. Depending on the type of cursor, you may even be able to move it to the previous row. ...
1 What is a query in a database? 1 What are query types in a database? 1 What is a join in SQL Server? 1 What are different types of joins in SQL Server? 1 What is Self-Join? 1 What is Cross-Join? 1 What is user defined functions? 1 What are all types of user...
This could mean using joins, writing subqueries, using SQL window functions, and similar techniques while observing query performance tuning. According to Indeed, the average salary for a data scientist in 2024 in the United States is $123,039. 2. Business analysts or business intelligence ...
SQL Server Interview Questions for a Data/BI Analyst If you're interviewing for a Data Analyst or BI Analyst role, you'll likely encounter questions focused on your ability to analyze and present data insights. Let's delve into some common interview questions tailored toward these positions. ...
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 in parent stored procedure?