Constraints can be at column level or table level. -- They are used to specify rules for ... DESC constraints; (otherwise SQL Server will name them with a random name, which makes it really difficult ...

A foreign key in SQL is a table-level construct that constrains one ... generally should only refer to the column to which they are placed, while table level constraints can refer to any columns in ...

An example could be when creating a table in SQL for Person ... are executed at the server level and reduce the need for additional checks and transactions. Check constraints in SQL help keep ...