- Simple Queries (4)
- Setting criteria using WHERE (5)
- Calculations (7)
- Calculations using dates (4)
- Basic joins (8)
- More exotic joins (2)
- Aggregation and grouping (8)
- Views (5)
- Subqueries (5)
- Stored procedures (5)
- Variables (8)
- Parameters and return values (11)
- Testing conditions (1)
- Looping (3)
- Scalar functions (6)
- Transactions (5)
- Creating tables (5)
- Temporary tables and table variables (9)
- Table-valued functions (6)
- Derived tables and CTEs (13)
- Dynamic SQL (4)
- Pivots (2)
- Triggers (2)
- Archived (70)
SQL | Archived exercise | Error trap when creating temp table
This exercise is provided to allow potential course delegates to choose the correct Wise Owl Microsoft training course, and may not be reproduced in whole or in part in any format without the prior written consent of Wise Owl.
You can learn how to do this exercise on the relevant Wise Owl classroom training course (sadly for the moment only in the UK).
You need a minimum screen resolution of about 700 pixels width to see our exercises. This is because they contain diagrams and tables which would not be viewable easily on a mobile phone or small laptop. Please use a larger tablet, notebook or desktop computer, or change your screen resolution settings.
If you haven't already done so, run the stored procedure in the above folder to generate a database of training courses and delegates.
Create a query to show all the people with really long names - similar to the following - and run it twice:
You should find that this displays only 3 people
When you run your query a second time, it should crash because the temporary table #BigPeople already exists. Apply error trapping at the top of the query such that:
- Your query attempts to delete the table
- If it already exists, the table is deleted and your query prints out a message saying that this has happened
- If it didn't already exist, you get a message saying that nothing was deleted
You can test out that this final possibility works by adding the following command at the end of your query:
This command would ensure that the table didn't exist the next time that you run the query
Optionally, save this query as Check deleting temp table.sql, then close it down.