Shulou(Shulou.com)06/01 Report--

Data Definition

CREATE, to create a new database object

ALTER, to change an aspect of the structure of an existing database object

DROP, to drop (remove) a database object

Data Manipulation and Transactions

INSERT, to add rows to a table

UPDATE, to change column values of existing rows

DELETE, to remove rows from a table

COMMIT, to confirm all pending changes of the current transaction

ROLLBACK, to cancel all pending changes and restore the original situation

DELETE empties a table; DROP removes a table. TRUNCATE allows you to delete all the rows in a table in an efficient (but irrevocable) way.

UPDATE changes the contents of a table; ALTER changes its structure.

You can undo the consequences of data manipulation with ROLLBACK; data definition commands are irrevocable.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.