What does the PRIMARY KEY constraint enforce in a DB2 table?
- Data type constraint
- Default value
- Referential integrity
- Uniqueness and not null
The PRIMARY KEY constraint in DB2 enforces uniqueness and not null for one or more columns in a table. It uniquely identifies each record in the table, preventing duplicate or null values in the specified column(s). This constraint is crucial for ensuring entity integrity and efficient data retrieval operations.
Loading...