Can two tables have the same primary key name? Explain.

Difficulty: 4/10

primary key naming, schema design, foreign key references

Can Different Tables Use the Same Primary Key Name?

Yes, two different tables can have primary keys with the same column name. Primary key names only need to be unique within the same table, not across the entire database.

1. Why Same Primary Key Names Are Allowed

1
Each table is independent, so constraints inside one table do not conflict with another.
2
Table structure and column names exist in separate namespaces — two tables can both have a column named id as their PRIMARY KEY.
3
Databases often use consistent naming patterns like id across multiple tables for clarity.

2. When It Might Matter

1
If tables are related using FOREIGN KEY constraints, the column names do not need to match — only the data types.
2
Using consistent names (e.g., customer_id, order_id) improves readability but is not required.

Example: Two Tables Sharing the Same Primary Key Name

Here, both tables have a primary key named id, and this is completely valid because each table manages its own primary key constraint.

Scenario Questions

0-2 years experience

Follow-up Questions