SQL statement syntax for adding fields to a table in oracle

The SQL statement used by oracle to add fields to a table is written in the SQL code www.2cto.com alter table TAB_SMS_BLACKLIST add (BLACK_TYPE NUMBER default 1 not null, COMPANY_ID NUMBER, BLACK_NAME VARCHAR2 (64 )); comment on column TAB_SMS_BLACKLIST.BLACK_TYPE is '-- blacklisted Level 1-enterprise level; 2-system level default: 1'; comment on column TAB_SMS_BLACKLIST.COMPANY_ID is' -- company No '; comment on column TAB_SMS_BLACKLIST.BLACK_NAME is '-- blacklist name (the owner of the number). The default phone number is stored.'; www.2cto.com remarks: TAB_SMS_BLACKLIST indicates the table name.