Alter Table Oracle
ALTER TABLE tablename MODIFY columnname varchar2(100)
Wrong Willet
ALTER TABLE tablename MODIFY columnname varchar2(100)-- ALTER TABLE <table> ADD <column> <type> <constraint>;
ALTER TABLE members ADD age NUMBER;
ALTER TABLE members ADD birth_date DATE NOT NULL;
ALTER TABLE members ADD registering DATE DEFAULT sysdate;
ALTER TABLE members ADD member_id NUMBER UNIQUE;ALTER TABLE table_name
ADD column_name column_definition;