Get data type of field in select statement in ORACLE

Question

Can I get data types of each column I selected instead of the values, using a select statement?

FOR EXAMPLE:

SELECT a.name, a.surname, b.ordernum 
FR         


        

Answer 1

I found a not-very-intuitive way to do this by using DUMP()

SELECT DUMP(A.NAME), 
       DUMP(A.surname), 
       DUMP(B.ordernum) 
FROM   customer A 
       JOIN orders B 
         ON A.id = B.id

It will return something like:

'Typ=1 Len=2: 0,48' for each column.

Type=1 means VARCHAR2/NVARCHAR2
Type=2 means NUMBER/FLOAT
Type=12 means DATE, etc.

You can refer to this oracle doc for information Datatype Code
or this for a simple mapping Oracle Type Code Mappings