- Tags: Keyword
- Categories: Reference, SQL Keywords, SQL Reference
Quick Reference
The ADD keyword is used to add columns or constraints to an existing table.
ADD COLUMN
The following adds the last_name column to the Customers table.
ALTER TABLE Customers
ADD last_name varchar(255);
ADD CONSTRAINT
The following adds a constraint named “key_customer” that is a PRIMARY KEY constraint on multiple columns (id and last_name).
ALTER TABLE Customers
ADD CONSTRAINT key_customer PRIMARY KEY (id, last_name);
We’d like to acknowledge that we learned a great deal of our coding from W3Schools and TutorialsPoint, borrowing heavily from their teaching process and excellent code examples. We highly recommend both sites to deepen your experience, and further your coding journey. We’re just hitting the basics here at 1SMARTchicken.
Why 1SMARTchicken?
See More →
Thanks for your support!
SQL Books
All are affiliate links. Thank you for your support!
SQL NOTES:
- Any work being done to modify the structure of a database or delete tables or the the database itself should only be done after making a recent backup
Feedback
If you see an error on the page or the code itself is incorrect or incomplete, or just plain wrong, please let us know. We’re always learning. NOTE: we do not sell your information and will not send you spam emails.
