Exercise: Retrieve aggregated data using variables

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The answer to the exercise will be included and explained if you attend the course listed below!

Category ==> SQL  (192 exercises)
Topic ==> Variables  (8 exercises)
Level ==> Relatively easy
Course ==> Advanced SQL
Before you can do this exercise, you'll need to download and unzip this file (if you have any problems doing this, click here for help). Once you've done this:
  1. Go into SQL Server Management Studio;
  2. Open the SQL file you've just unzipped (you can press CTRL + O to do this); then
  3. Execute this script.

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The aim of this exercise is to summarise events using the MIN, MAX and COUNT functions:

Variable Aggregate

The snag?  You're not allowed to use GROUP BY!

To do this, create variables to hold each of the aggregates:

Variable What it will hold eventually
@EarliestDate The earliest date
@LatestDate The latest date
@NumberOfEvents The number of events
@EventInfo The title Summary of events

Now use a single SELECT clause to set the value for all of these variables (alternatively you could use a series of subqueries).

Write another SELECT clause to show the value of the variables, to show the summary output shown above.

Optionally save this as The early, the late and the rest.sql and close it down.

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