Omitting a WHERE clause will delete all rows from a table.
DELETE FROM Employees
See TRUNCATE documentation for details on how TRUNCATE performance can be better because it ignores triggers and indexes and logs to just delete the data.
Use this to reset the table to the condition at which it was created. This deletes all rows and resets values such as auto-increment. It also doesn't log each individual row deletion.
TRUNCATE TABLE Employees
It is possible to DELETE data from a table if it matches (or mismatches) certain data in other tables.
Let's assume we want to DELETEdata from Source once its loaded into Target.
DELETE FROM Source
WHERE EXISTS ( SELECT 1 -- specific value in SELECT doesn't matter
FROM Target
...
