WISE OWL EXERCISES
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SQL | Archived exercise | Fn to count trainer ids
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If you haven't already done so, run the stored procedure in the above folder to generate a database of training courses and delegates.
Each row in the tblSchedule table contains a column called TrainerIds, giving details of who is assigned to train on the course:
Scheduled course 1, for example, has trainers number 21 and 93 assigned to it
We will create a function called fnCountIds to count how many trainers there are assigned to each course (note that exactly the same function could also count how many resources are assigned). The following code excerpt contains an idea to help you do this:
Count the number of trainers by seeing how long the string of ids is with and without its commas, and then taking the difference between these two numbers
Incorporate your function in a query to count the number of trainers assigned to a course:
The first few rows of the final query, sorted by course start date
Optionally, save the code to generate your function as Count trainers.sql, then close it down.