Final answer:
The correct answer is a) Self-join. A self-join is when a table is joined to itself, but it is not defined by non-equality conditions. Non-equality joins use comparison operators like > or < in the join condition.
Step-by-step explanation:
The question refers to a type of SQL join that is not specifically for combining rows based on equal values in two tables. The correct answer to the question is a) Self-join. A self-join is a special case where a table is joined with itself, but it is not necessarily defined by non-equality conditions.
Join operations like inner, outer (which can be further divided into left, right, or full), and cross joins are also used to combine rows from two or more tables based on a related column between them. However, these joins do not inherently mean the table is joined to itself nor do they imply a non-equality condition.
To perform a non-equality join, you would use comparison operators such as >, <, >=, or <= in the ON clause of a join statement, which can be applied in self-joins and other types of joins.