Mysql quiz and mysql quiz

Source: Internet
Author: User

Mysql quiz and mysql quiz

1. the user logon log table xes_user_login_logs is as follows:

(1) retrieve user IDs that have been logged on more than twice (SQL statement)

Select user_id from vvt_ceshi group by user_id having (count (user_id)> 1;
HAVING is like the WHERE condition, used to retrieve a dataset according to specified requirements. However, the WHERE clause is generally used to specify conditions for data queries, and HAVING is used to specify conditions for group by grouping.

(2) retrieve the total number of logins that exceeds two (SQL statement)

Select count (sum) from (select count (user_id) as sum from vvt_ceshi group by user_id having (count (user_id)> 1) as B;

2.

 

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.