MS SQL Aggregate Functions for beginners - COUNT, SUM, MAX, MIN

Описание к видео MS SQL Aggregate Functions for beginners - COUNT, SUM, MAX, MIN

This is a Microsoft SQL tutorial on Aggregate Functions. This includes COUNT, SUM, MAX, MIN and AVG. I will show, through examples, how to write Aggregate Functions, limiting results and error handling.

Errors discussed:
Column is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference.

Комментарии

Информация по комментариям в разработке