Do data scientists need to know SQL?

1. A Data Scientist needs SQL to handle structured data. As the structured data is stored in relational databases. Therefore, to query these databases, a data scientist must have a good knowledge of SQL commands.

How long does it take to write SQL queries?

It should take an average learner about two to three weeks to master the basic concepts of SQL and start working with SQL databases. But in order to start using them effectively in real-world scenarios, you’ll need to become quite fluent; and that takes time.

Is it worth to learn SQL?

SQL is still a very valuable skill to learn and master. Despite the proliferation of many NoSQL and hybrid SQL-NoSQL solutions, a lot of analytics software interact through SQL to read the data. The database could be document or key-value oriented but it will most likely understand SQL queries (or a very close flavor).

How much coding is required for a date in a query?

No extra coding required. Also note that your examples actually only have one date that is not of the same Month, Week, or Day (within one day), although in my example I required Days to be of the same day as the query to make it look a bit different.

How to get the monthly data from the joining date?

To get the monthly data we will first need to retrieve the month from the joining date and time column and apply that value as the grouping criteria. Further, we want to retrieve the sum of the rate in a monthly format.

How do I get the monthly data from the rate column?

To get the monthly data we will first need to retrieve the month from the joining date and time column and apply that value as the grouping criteria. Further, we want to retrieve the sum of the rate in a monthly format. Hence, we will use the aggregate function named SUM () to get the total value of the rate column.

How to retrieve the data in a month’s format?

We can retrieve the data in a month’s format by grouping the resultset based on the month. For this, some of the columns of the table from which the data is being required must contain the month value or date value from where the month can be retrieved.