SIP requires port ________ to be open. A) 47 B) 505 C) 3434 ...

[acc299]

SIP requires port ________ to be open.
 
  A) 47
  B) 505
  C) 3434
  D) 5060

Question 2

Explain the three classes of SQL commands and when they would be used.
 
  What will be an ideal response?

[jojobee318]

Answer to Question 1

Answer: D

Answer to Question 2

There are three classes or types of SQL commands. Data definition language commands are used to create tables, alter and drop tables, views and indexes. These commands are used to build the structure of the database as well as some additional objects. The next type is Data Manipulation Language commands, which are used to maintain and query a database. Commands in this class include select, update, delete and insert. The last type is the data control language commands, which are used to grant and revoke privileges on tables and other objects in the database.