Computer Science
Assertion. In the result produced by a join query, there may be multiple identical columns in the final result, but not always.
Reason. The join in which only one of the identical columns (coming from the joined tables) exists, is called a Natural join.
SQL Joins & Grouping
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Answer
(a)
Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
Explanation
In the result produced by a join query, there may be multiple identical columns in the final result, but this is not always the case. Depending on the type of join and the columns involved, duplicate columns may or may not appear in the result set. A Natural join is a type of join in SQL where only one of the identical columns (coming from the joined tables) exists in the final result.
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Related Questions
Assertion. Generally, a join query combines rows from multiple tables having some common column(s) and a joining condition, but not always.
Reason. A Cartesian product is an unrestricted join where all possible combinations of rows from multiple tables are created without any condition on them.
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Reason. The join queries only produce combined rows from tables having some common column, when compared for equality.
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