Unique Constraint
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What is Unique Constraint?
A unique constraint ensures that all values in a column (or a group of columns) are different. It prevents duplicate entries, maintaining data integrity by enforcing uniqueness for the specified field(s). This is useful for fields like email addresses or usernames, where each record should have a distinct value.
Free resources to learn Unique Constraint
- ArticleSQL UNIQUE Constraint
More in stage 5: Aggregate Queries
Unique Constraint: common questions
Can I learn Unique Constraint in Hindi?
This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Unique Constraint in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.
Is this Unique Constraint tutorial for beginners?
It is lesson 39 of 112 in the free SQL roadmap, in stage 5, Aggregate Queries. If you are new to SQL, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.