Master SQL for Data Analysis - Outer-Join

The video tutorial explains SQL join operations, focusing on inner and outer joins. It covers the differences between inner joins, which exclude unmatched rows, and outer joins, which include them. The tutorial details left, right, and full outer joins, providing examples and comparisons to illustrate their use cases and effects on data retrieval.

What is the primary purpose of using a join in SQL?

• To delete data from tables

• To create new tables

• To update existing records

• To combine data from two tables based on a condition

Which type of join would you use to include all rows from the left table and only matched rows from the right table?

• Inner Join

• Right Outer Join

• Left Outer Join

• Full Outer Join

In the example provided, why are customers Idan and Tom still included in the result set when using a left outer join?

• Because they have the highest customer IDs

• Because they are from a specific city

• Because the left outer join includes all rows from the left table

• Because they have matching orders

What happens to unmatched rows from the left table when using a right outer join?

• They are excluded from the result set

• They are included in the result set

• They are merged with the right table

• They are duplicated in the result set

Which join type returns all records from both tables, regardless of whether there is a match?

• Left Outer Join

• Full Outer Join

• Right Outer Join

• Inner Join

What is a potential drawback of using a full outer join?

• It can return a very large result set

• It excludes unmatched rows from both tables

• It requires more complex SQL syntax

• It only returns matched rows

What is the first step performed by the database management system when executing a full outer join?

• Performing a left outer join

• Performing a right outer join

• Performing a cross join

• Performing an inner join