Master SQL for Data Analysis - Grouping Rows (GROUP BY and HAVING)

The video tutorial covers the use of the GROUP BY statement in SQL to group rows based on column values and perform actions like filtering and calculations. It explains the syntax and usage of GROUP BY with examples, including working with the Credits table to count distinct actors. The tutorial also discusses combining data from multiple tables using keys and advanced grouping techniques with multiple columns. Finally, it explains the order of SQL query execution, emphasizing the importance of understanding each stage.

What is the primary purpose of the GROUP BY statement in SQL?

• To sort the data in ascending order

• To group rows that have the same values in specified columns

• To update values in a specific column

• To delete duplicate rows from a table

Which of the following is NOT typically used with the GROUP BY statement?

• JOIN

• MAX

• COUNT

• SUM

When grouping by a single column, what must be true about the columns in the SELECT statement?

• They must be sorted in ascending order

• They must be included in the GROUP BY clause

• They must all be aggregated

• They must be unique

How can you replace a title ID with an actual title name when combining data from multiple tables?

• By using a DISTINCT keyword

• By using a HAVING clause

• By using a JOIN operation

• By using a subquery

What is the role of aliases when combining data from multiple tables?

• To sort the final output

• To filter rows before grouping

• To provide short names for tables

• To rename columns in the final output

What is the main difference between the WHERE and HAVING clauses?

• WHERE is for joining tables, HAVING is for aggregating

• WHERE is used for sorting, HAVING is for filtering

• WHERE filters rows before grouping, HAVING filters after

• WHERE is for selecting columns, HAVING is for ordering

In SQL, what is the correct order of execution for a query?

• WHERE, FROM, SELECT, GROUP BY, ORDER BY, HAVING

• FROM, WHERE, GROUP BY, HAVING, SELECT, ORDER BY

• ORDER BY, SELECT, FROM, WHERE, GROUP BY, HAVING

• SELECT, FROM, WHERE, GROUP BY, HAVING, ORDER BY