Replace SQL Null Values with SQLPLUS Set Null Command

You can use the SQL NVL function to handle the null values in the query. Second option is SQLPLUS set null feature to replace the null values with user defined values.

See an example here.

We have a table DEPT with some of the HOD column values are null. 

SQL> select dname, HOD from dept

SQL> /

DNAME          HOD

-------------- ------------------------------

ACCOUNTING     Jones

RESEARCH

SALES

OPERATIONS     Peter 

I am setting the null values to "Not Yet Assigned” as replacement.

SQL> set null "Not Yet Assigned"

SQL>/

DNAME          HOD

-------------- ------------------------------

ACCOUNTING     Jones

RESEARCH       Not Yet Assigned

SALES          Not Yet Assigned

OPERATIONS     Peter