adding default value to 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: set default column value sql

Name Varchar(255) default "Fred"

Example 4: add column alter table default value

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

Example 5: alter column to not null with default value sql server

ALTER TABLE SomeTable
        ADD SomeCol Bit NULL --Or NOT NULL.
 CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is autogenerated.
    DEFAULT (0)--Optional Default-Constraint.
WITH VALUES --Add if Column is Nullable and you want the Default Value for Existing Records.