Question

SELECT * FROM heroes h, skills s WHERE h.skill_code = s.skill_code;

Answer 1

The SQL query performs an inner join operation between two tables, heroes and skills, using a WHERE clause to specify a match on the skill_code fields of both tables.

Step-by-step explanation:

The query provided:

SELECT * FROM heroes h, skills s WHERE h.skill_code = s.skill_code;

is a SQL join operation that is used to retrieve data from two tables: heroes and skills. These tables are aliased as h and s respectively. The WHERE clause specifies the condition for the join, which in this case is that the skill_code field in the heroes table must match the skill_code field in the skills table. This SQL statement will return a combined result set with all columns from both heroes and skills where the join condition is true.

It's important to note that this type of join is known as a cross join or Cartesian join since it does not explicitly use the JOIN keyword, but it functions as an inner join due to the WHERE clause that links the two tables.