Data set:

CASE1:

kamini,mishra
priya,

CASE2:

kamini,mishra
priya,null

Code:(for both the case)

CREATE TABLE Table2(name STRING, lastname STRING)ROW FORMAT DELIMITED FIELDS TERMINATED BY ',';

LOAD DATA LOCAL INPATH '/home/edureka/Desktop/kk' INTO table Table2;

SELECT * from table where lastname=""; // FOR null values where null is given and blank both.

SELECT * from table where lastname="null";   // FOR null values where null is given.