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.
Each table is independent, so constraints inside one table do not conflict with another.
Table structure and column names exist in separate namespaces — two tables can both have a column named
idas their PRIMARY KEY.Databases often use consistent naming patterns like
idacross multiple tables for clarity.
If tables are related using FOREIGN KEY constraints, the column names do not need to match — only the data types.
Using consistent names (e.g.,
customer_id,order_id) improves readability but is not required.
Here, both tables have a primary key named id, and this is completely valid because each table manages its own primary key constraint.