Epsilon Senior Business Analyst Interview Questions and Answers

Groupby is used to group data based on a specific column, while having is used to filter grouped data based on a condition.

• Groupby is used to group data based on a specific column in SQL.

• Having is used to filter grouped data based on a condition in SQL.

• Groupby is typically used with aggregate functions like SUM, COUNT, AVG, etc.

• Having is used after the GROUP BY clause to filter groups based on a condition.

Cross join combines every row from one table with every row from another table. Self join joins a table with itself.

• Cross join produces a Cartesian product of the two tables involved.

• Self join is used to join a table with itself, typically to compare rows within the same table.

• Cross join does not require a common column between the two tables.

• Self join requires a common column to join the table with itself.

• Example of c...read more