Consider the two tables ping and pong created above and the respective instances. Does the

execution of each of the following SQL statements cause any constraint violation? If yes, describe the

constraint that is being violated.

$1.$ INSERT INTO pong VALUES $(2,3,$ 'kot'$)$;

$2.$ INSERT INTO pong VALUES $(2,3,\text{'}$ko$\text{'})$;

$3.$ INSERT INTO pong VALUES $(4,4,\text{'}$so$\text{'})$;

$4.$ UPDATE pong SET pid$=5$ WHERE id$=1$;

$5.$ DELETE FROM ping where id$=3$;

$6.$ INSERT INTO pong VALUES $($NULL$,1,\text{'}$so$\text{'})$;

$7.$ INSERT INTO pong VALUES $(5,$ NULL, $\text{'}$so$\text{'})$;

$8.$ UPDATE ping SET id$=$NULL WHERE serve$=$'set';