Reference no: EM133300648

Grouping Data

We can group the result set in SQL on multiple column values. When we define the grouping criteria on more than one column, all the records having the same value for the columns defined in the group by clause are collectively represented using a single record in the query output. All the column values defined as grouping criteria should match with other records column values to group them to a single record. Most of the time, group by clause is used along with aggregate functions to retrieve the sum, average, count, minimum or maximum value from the table contents of multiple tables joined query's output.

Questions

1. You are tasked to develop a report that includes the number of employees who departed their positions, organized by the year they left. The tasks they completed are also essential. The results must be sorted in decreasing order by employee count in each category/group. The year, the JOB ID, and the num (12 Marks)

2. You are requested to organize your company's data. Can you count the records in each category by first dividing the employee records by year of employment, then by job, and lastly by salary?

3. Describe how you can run a script on SQL*PLUS.