add a column with default value 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: How to Add a Default Value to a Column in MS SQL Server

ALTER TABLE <table_name> ADD DEFAULT <DEFAULT_VALUE> FOR <NAME_OF_COLUMN>