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CBSE Class 11 Informatics Practices Question 28 of 87

Structured Query Language (SQL) — Question 9

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9
Question

Question 9

Which of the following types of table constraints will prevent the entry of duplicate rows?

  1. Foreign Key
  2. Distinct
  3. Primary Key
  4. NULL
Answer

Primary Key

Reason — A primary key is a set of one or more attributes or fields that uniquely identifies a tuple or row in a table. Therefore, it ensures that each row in the table is unique and prevents the entry of duplicate rows.