Introduction - If you have any usage issues, please Google them yourself
four development process, the statement alter table people add (phone_number varchar2 (10)) is the role of Table A revised structure for the people Table B added constraint, constraint name of the people phone_number Table C to add a name is phone_number. yes varchar2 data type, length is the answer above 10 D falsities 5, () BLOB and CLOB the difference is only a CLOB type of characters stored data, and BLOB no restrictions placed only B BLOB data type characters, and CLOB no restrictions only C CLOB deposit of less than 4000 bytes of data, and BLOB can be stored more than 4,000 gigabytes of data storage D BLOB only less than 4000 bytes of data, and CLOB can be stored more than 4,000 gigabytes of data on six, and stored in essence, it was A anonymous PL/SQL block, it can be given the pa