alter table add column with default value null in sql code example

Example 1: add column table sql default value

ALTER TABLE users
ADD visit_number INT DEFAULT 0;

Example 2: alter table add column with default value

ALTER TABLE Protocols
ADD ProtocolTypeID int NOT NULL DEFAULT(1)

Example 3: add column alter table default value

ALTER TABLE PERSON
ADD IS_ACTIVE VARCHAR2(1) DEFAULT 'N' NOT NULL