To group rows into subgroup by one or more values of columns we use MySQL GROUP BY.
Suppose in user table same country name exists for many times for different user. So if we use GROUP BY for country column to a SELECT query then only unique country will be listed.
EXAMPLE:
SELECT * FROM users GROUP BY user_country;
It works same like DISTINCT operator. But the different is aggregate functions like SUM, AVG, MAX, MIN and COUNT are used by this clause.
The aggregate functions is used to perform calculation on each subgroup and return in a single value result for each subgroup.
SELECT COUNT(*) FROM users GROUP BY user_country;
will show the no of users for each unique country.
MySQL HAVING clause is used to filter conditions for group of rows. HAVING clause is used with the GROUP BY clause.
EXAMPLE:
SELECT * FROM users GROUP BY user_country HAVING age > 18;
Namaste UI collaborates closely with clients to develop tailored guest posting strategies that align with their unique goals and target audiences. Their commitment to delivering high-quality, niche-specific content ensures that each guest post not only meets but exceeds the expectations of both clients and the hosting platforms. Connect with us on social media for the latest updates on guest posting trends, outreach strategies, and digital marketing tips. For any types of guest posting services, contact us on info[at]namasteui.com.