How to do alter table using Check Constraint - SQL Server

Question

CREATE TABLE publishers
(
    PublisherName    varchar(75),
    City                    varchar(35),
    PublisherState    char(2),
    Country            varchar(4)
)
GO 

-- modify publishers so that state must be two letters

ALTER TABLE publishers
    ALTER COLUMN publisherstate char(2) CHECK (publisherstate LIKE '[A-Za-z][A-Za-z]')​

Answer 1

You have to mention the Constraint Name and Check.

Try this:

alter table publishers
add constraint codeCheck check (PublisherState like '[A-Za-z][A-Za-z]');