Database checks and constraints
The following constraints support relational database objects for controlling and limiting operations if they’re not controlled by primary and foreign keys. Adding too many constraints to a single table is also an overhead for the database. The internal operations of each check will cause performance degradation in larger datasets.
Let’s take a closer look at each.
Check constraint
This ensures that all values in a column satisfy a specific condition. It acts as a gatekeeper, only allowing data that satisfies the condition to be entered into the column. For example, a check constraint on an age column could ensure that only values greater than 0 are entered.
Default constraint
This constraint assigns a default value to a column when no value is specified. It’s useful for setting standard values for a column. For instance, a default constraint could automatically set a status column to active when a new record is created...
