What is the main purpose of a FOREIGN KEY constraint?

Problem Statement

Explanation

A foreign key enforces referential integrity. Values in the child column must exist in the referenced parent key. This prevents orphan records and maintains valid relationships as data changes.

Code Solution

SolutionRead Only

CREATE TABLE orders (
  id BIGINT PRIMARY KEY,
  customer_id BIGINT REFERENCES customers(id)
);

Practice Sets

This question appears in the following practice sets:

Constraints, Keys & Data Integrity

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What is the main purpose of a FOREIGN KEY constraint?

Problem Statement

Explanation

Code Solution

Practice Sets

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Master Interviews Anywhere, Anytime

What is the main purpose of a FOREIGN KEY constraint?

Problem Statement

Explanation

Code Solution

Practice Sets

Related Questions

Which SQL statement retrieves all columns and rows from a table named employees?

Which clause filters rows before aggregation and affects which rows are grouped?

What is the default sort order when ORDER BY is used without ASC or DESC?

Which construct is commonly used to paginate results in SQL engines like Postgres and MySQL?

Which predicate correctly checks for missing values in standard SQL?

More from SQL & Databases

Master Interviews
Anywhere, Anytime