Great! We've reached the final section for this part. Let's review what we've learned.

A database architect can define a default value for a column in a table. If that's the case, you can use default value:

• In an INSERT statement:

INSERT INTO Author (Id, FirstName, LastName, Photo, CreateDateTime, IsActive) 
VALUES (120, N'Gary', N'Brown', N'imgs/gary.jpg', '2018-08-25', DEFAULT);

• By omitting columns in INSERT:

INSERT INTO Author (Id, FirstName, LastName) 
VALUES (121, N'Mary', N'Taylor');

• During an UPDATE operation:

UPDATE Author
Photo = DEFAULT
WHERE Id = 120;

Plus, you learned how to auto-generate unique values by:

• Using IDENTITY and omitting the name of the Id column:

INSERT INTO Author(FirstName, LastName) 
VALUES (N'Stanley', N'Lewis');

The Id column, which isn't listed in the query, uses IDENTITY to auto-generate values unique to this column.

• Using NEWID():

INSERT INTO Author (Id, FirstName, LastName,  Photo)
VALUES (NEWID(),  N'Eva', N'Rayan', N'imgs/lisa3.jpg');

• Using a sequence:

INSERT INTO Author (Id, FirstName, LastName, IsActive) 
VALUES (NEXT VALUE FOR IdSeq,  N'Miriam', N'Clerk', 1);

Auto-generated values from the same sequence can be used in multiple tables, and each value will be unique.