Answers for "mysql alter table add column default value"

postgresql change column type

ALTER TABLE assets ALTER COLUMN name TYPE VARCHAR;

mysql add column default value

ALTER TABLE table1 ADD COLUMN foo INT DEFAULT 0;

alter table delete column

ALTER TABLE "table_name" DROP "column_name";

how to add default constraint in mysql

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

mysql add column with default value

-- ALTER TABLE tbl_name ADD COLUMN column_name column_definition 
--		[FIRST|AFTER existing_column];
ALTER TABLE office ADD COLUMN phone VARCHAR(200) DEFAULT '000' AFTER name;
ALTER TABLE office ADD COLUMN flag INT(1) FIRST;
ALTER TABLE office ADD COLUMN last_col INT(2);	-- Last column is default position
-- ↓ Test it (Fiddle)

set default column value sql

Name Varchar(255) default "Fred"