alter tabel code example

Example 1: alter table add column

ALTER TABLE table
ADD COLUMN column VARCHAR (255) NOT NULL AFTER column;

Example 2: sqlserver add column to table

ALTER TABLE dbo.doc_exa 
ADD column_b VARCHAR(20) NULL, 
	column_c INT NULL ;

Example 3: orcale sql change column type

ALTER TABLE table_name 
MODIFY column_name action;