note

#11【SQL】Distinct & GROUP BY 使い方、使い分け。

今回も #基本情報技術者試験対策として、#SQL 学習しました。今回はまとめる句のDistinct & GROUP BY。 とりあえず、ただ列をまとめるだけならどちらでもいいかな。と言う感じです。 しかしながら、データを触る場合、そのまとめた列をどうするのか、それに ...
GitHub

is-distinct-from-transact-sql.md

Compares the equality of two expressions and guarantees a true or false result, even if one or both operands are NULL. Any valid expression. The expression can be a column, a constant, a function, a ...
GitHub

approx-count-distinct-transact-sql.md

This function returns the approximate number of unique non-null values in a group. :::image type="icon" source="../../includes/media/topic-link-icon.svg" border ...
YouTube on MSN

I learned SQL in 15 minutes! Here's how

Learn SQL basics in just 15 minutes with this tutorial focused on using SQL with MySQL. Topics covered include: - What SQL is and an overview of relational database management systems - Installing ...