Question

Given the provided data for an outfit generator with outfit IDs and piece IDs, how many records would be included in the result set for the following query?

SELECT [ ], [ ] FROM outfit CROSS JOIN piece;
(Note: Replace [ ] with appropriate column names or expressions.)

Answer 1

The query will produce a Cartesian product, resulting in a number of records equal to the product of the number of rows in the outfit table and the number of rows in the piece table.

Step-by-step explanation:

The question involves determining the number of records in the result set for a SQL query using a CROSS JOIN between two tables: outfit and piece. To answer this, replace the [ ] in the query with the column names from the respective tables, but for counting the number of records, actual column names are irrelevant. The key here is understanding that a CROSS JOIN produces a Cartesian product of the two tables, meaning every row from the first table (in this case, outfit) is joined with each row from the second table (in this case, piece).

Assuming there are m rows in the outfit table and n rows in the piece table, the result set will contain m x n records. Therefore, to know the exact number of records in the result set, one must know the actual number of rows in both outfit and piece tables.

The OUTER JOIN in SQL is used to combine rows from two or more tables even if there is no match between the columns being joined. In this case, the CROSS JOIN is used, which produces a cartesian product of the two tables, resulting in each record from the first table being combined with every record from the second table. As a result, the number of records in the result set for the given query can be calculated by multiplying the number of records in the outfit table with the number of records in the piece table.

For example, if the outfit table has 5 records and the piece table has 7 records, then the result set would include a total of 35 records.