How to use a calculated column to calculate another column in the same view

Question

I am hoping you can help with this question. I am using Oracle SQL (SQL Developer for this view)...

If I have a table with the following columns:

• Co

Answer 1

In SQL Server

You can do this using With CTE

WITH common_table_expression (Transact-SQL)

CREATE TABLE tab(ColumnA DECIMAL(10,2), ColumnB DECIMAL(10,2), ColumnC DECIMAL(10,2))

INSERT INTO tab(ColumnA, ColumnB, ColumnC) VALUES (2, 10, 2),(3, 15, 6),(7, 14, 3)

WITH tab_CTE (ColumnA, ColumnB, ColumnC,calccolumn1)  
AS  
(  
Select
    ColumnA,
    ColumnB,
    ColumnC,
    ColumnA + ColumnB As calccolumn1
  from tab
)  

SELECT
  ColumnA,
  ColumnB,
  calccolumn1,
  calccolumn1 / ColumnC AS calccolumn2
FROM  tab_CTE

DBFiddle Demo