how to set a default value for a column in sql code example

Example 1: add column table sql default value

ALTER TABLE users
ADD visit_number INT DEFAULT 0;

Example 2: how to add default constraint in mysql

ALTER TABLE "name_table" ALTER "name_column" 
SET DEFAULT value_default;

Example 3: default number in sql

//Sql Server

//Add a table 
ALTER TABLE clients ADD Points INT DEFAULT 0
//Edit an existing table
ALTER TABLE clients ADD CONSTRAINT points DEFAULT 0 FOR Points

Example 4: 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>