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Primary vs Foreign Keys

EasySQL · PostgreSQL00:00
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Your question is Primary vs Foreign Keys. Start with the requirements and the two tables on the right.

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Problem

Explain the difference between a primary key and a foreign key in SQL.

Use the Airtel customer and subscription tables below to identify the key columns in each table and show how they relate.

Output

  1. One row per key column in the schema
  2. Columns: table_name, column_name, key_type, references_table, references_column
  3. Include both primary keys and foreign keys, ordered by table_name, then key_type, then column_name

Schema

airtel_customers
ColumnTypeDescription
customer_idPKINTUnique customer identifier
customer_nameVARCHAR(100)Customer full name
cityVARCHAR(50)Customer city
airtel_subscriptions
ColumnTypeDescription
subscription_idPKINTUnique subscription identifier
customer_idINTCustomer identifier referenced from airtel_customers
plan_nameVARCHAR(50)Subscription plan name
Tablesairtel_customersairtel_subscriptions
Your solutionPostgreSQL
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