ALTER TABLE SET Column code example
Example 1: sql change column types
ALTER TABLE table_name
ALTER COLUMN column_name datatype;
-- Example
ALTER TABLE product
ALTER COLUMN description VARCHAR(250);
Example 2: alter table modify column
-- ORACLE 18c
ALTER TABLE table_name
MODIFY column_name datatype;
-- Example
ALTER TABLE product
MODIFY description VARCHAR2(500 char);
Example 3: sql change column in existing table
'This adds 'NOT NULL' to excisting column counting in the table mytable'
ALTER TABLE mytable ALTER COLUMN counting INT NOT NULL;