高频题（0）
1. General SQL questions
| 1. How many new subscribers have we received every month starting Jan 2017?
2. How does that metric compare to the same month prior year'
3.What is the conversion rate of signups for Dec 2018?
4. There' s another table (Free Subs) with companyIDs that got a free subscription.How do we exclude them from our previous metrics？
Table:
+---------+---------+---------------+--------------+---+------+|
companyid I signupdate l subscriptiondate l terminationdate l year l month
+---------+---------+---------------+--------------+---+------+|
|13343128 | 2020-02-13 |2020-02-14 I NULL || 13343124 | 2020-02-13 I 2020-02-14 |NULL || 13343100 I 2020-02-13 I 2020-02-14 I NULL ll 13343090 | 2020-02-13 I NULL || 2020-02-13 || 13343074 I 2018-02-13 I 201 8-02-14I NULL ll 13342758 | 2018-03-23 I 2018-03-24 I NULL || 13342732 | 2018-04-05 | 2018-04-05 I NULL || 13342730 |2018-09-13 |NULL |I 2018-09-13 || 1342720 | 2017-01-05 |2017-01-06 I 2018-02- 13 || 11343128 |2017-02-08 |2017-02 -08 I 2018-08-13 || 11342610 |2017-03 -23 | 2017-04-23I 2018-11-21 || 11342720 | 2017-03-29 |2017-03-30
2. How does that metric compare to the same month prior year'
3.What is the conversion rate of signups for Dec 2018?
4. There' s another table (Free Subs) with companyIDs that got a free subscription.How do we exclude them from our previous metrics？
Table:
+---------+---------+---------------+--------------+---+------+|
companyid I signupdate l subscriptiondate l terminationdate l year l month
+---------+---------+---------------+--------------+---+------+|
|13343128 | 2020-02-13 |2020-02-14 I NULL || 13343124 | 2020-02-13 I 2020-02-14 |NULL || 13343100 I 2020-02-13 I 2020-02-14 I NULL ll 13343090 | 2020-02-13 I NULL || 2020-02-13 || 13343074 I 2018-02-13 I 201 8-02-14I NULL ll 13342758 | 2018-03-23 I 2018-03-24 I NULL || 13342732 | 2018-04-05 | 2018-04-05 I NULL || 13342730 |2018-09-13 |NULL |I 2018-09-13 || 1342720 | 2017-01-05 |2017-01-06 I 2018-02- 13 || 11343128 |2017-02-08 |2017-02 -08 I 2018-08-13 || 11342610 |2017-03 -23 | 2017-04-23I 2018-11-21 || 11342720 | 2017-03-29 |2017-03-30
2. Data Analysis using Python Dataframes
You will be given a dataset and are required to solve a problem using Python dataframes. The solution should be executable in the terminal and the task is expected to be fairly simple.
3. Describe your ML project experience and follow-up details
During the interview, you will be asked to describe your machine learning project experiences in detail. The interviewer will focus on the projects you mention and may ask in-depth questions to understand specific aspects of your work.
4. Write a SQL Query
Write a SQL query that returns user ids who are both posters and bidders.
5. SQL vs NoSQL Choice Discussion
Discuss the choice between SQL and NoSQL databases in the context of the craft demo project you presented.
