Dbs101_flipclass3

Null values and set operations in SQL.

Summary of the class.

After the class, we started our flip class discussion among the expert group members sharing the same topic, and we browsed for more information on set operations. Thirty minutes were provided for us to discuss the topic, and we noted all the important points. We then presented our own points within the group. After the discussion, we were given another 30 minutes to explain our topic to the home group, and the other team members joined the home group and presented on the topic of NULL values.

My learning.

As a member of the Expert group, I learned the concept of SQL Set Operation, which is nothing but an operation used to combine two or more SQL SELECT statements. It consists of four types of set operations, namely Union Set Operation, Union All Set Operation, Intersection Set Operation, and Minus Set Operation. For us to successfully use a set operation, we need to keep in mind some conditions, such as the data type and the order of the column must be the same. If not, the set operation won’t run. A Union Set Operation is a set operation that is used to combine two or more SQL SELECT queries, which will remove all the duplicate values. Union All will also combine two or more SQL SELECT queries but will not remove duplicates. Intersection Set Operation is a type of operation that combines two or more SQL SELECTION queries in such a way that it only returns data that are common in both tables, whereas a Minus Set Operation combines two or more tables and returns only those data that are not present in the first one and absent in the second one. After the discussion in the home group, I learned a new topic on Null values, which is nothing but an empty field with no values. But the empty value is not zero, and Null values can be found using IS NULL or IS NOT NULL operation.

Suggestion.

The learning process would be better if there was some coding task that we can perform using those set operations.