Querying databases may be the most common use case, but you will usually need to put some data in there in the first place. One of the most commonly used features when inserting records into a relational DB is the identity column. This is an auto-incrementing ID that is generated by the database, and doesn't need to be supplied when adding data.
For example, in our BlogPost table from earlier, the BlogPostId column is created as INTIDENTITY(1,1). This means that it's an integer value starting at one and increasing by one for every new row. You INSERT into this table, without specifying BlogPostId, like so:
INSERT INTO BlogPost (Title, Content)
VALUES ('My Awesome Post', 'Write something witty here...')
Identities can be very ...
