How can I insert a hyphen in the middle of an alpha numerical string?

Question

My query currently produces output with the Part Number as one value:

SELECT UPPER(PartNumber)AS "Part Number",
    INITCAP(PartDesc)AS "Description"
FROM Part 
WHERE UnitPrice*UnitsOnHand <1000
ORDER BY PartDesc DESC;

Part Number Description                            
----------- ----------------------------------------
BA74        Baseball Bat                             
CA14        Skillet - 12 Inch                        
AZ52        Roller Skates                            

The result should still be 2 columns, but modified:

Part Number Description                            
----------- ----------------------------------------
BA-74       Baseball Bat                             
CA-14       Skillet - 12 Inch                        
AZ-52       Roller Skates                            

Part Number will always have alpha/numeric characters, Description is just alpha. What I need to be able to do is insert a hyphen between the alpha and numerical characters. They will always be alpha/numeric never change.

Answer 1

The question is still missing some details, but if I've got your pattern right, and you want to separate the first block of just alphabetic characters from everything else with a hyphen, you can use a pair of regular expressions and string concatenation:

SELECT UPPER(
      REGEXP_SUBSTR(PartNumber, '[[:alpha:]]+')
      ||'-'||
      REGEXP_SUBSTR(PartNumber, '[^[:alpha:]]+.*')
    ) AS "Part Number",
    INITCAP(PartDesc)AS "Description"
FROM Part 
WHERE UnitPrice*UnitsOnHand <1000
ORDER BY PartDesc DESC;

Part Number           Description                  
--------------------- ------------------------------
CA-14                 Skillet - 12 Inch              
AZ-52                 Roller Skates                  
BA-74                 Baseball Bat                   

This will work for more complicated values, as long as the part number always starts with a character:

WITH Part AS (
    SELECT 'b9a74' AS PartNumber, 'baseball BAT' AS PartDesc,
        20 AS UnitPrice, 20 AS UnitsOnHand FROM DUAL
    UNION ALL SELECT 'ca14a1', 'sKiLlEt - 12 iNCH', 20, 20 FROM DUAL
    UNION ALL SELECT 'aza52', 'roller sKaTeS', 20, 20 FROM DUAL
)
SELECT UPPER(
      REGEXP_SUBSTR(PartNumber, '[[:alpha:]]+')
      ||'-'||
      REGEXP_SUBSTR(PartNumber, '[^[:alpha:]]+.*')
    ) AS "Part Number",
    INITCAP(PartDesc)AS "Description"
FROM Part 
WHERE UnitPrice*UnitsOnHand <1000
ORDER BY PartDesc DESC;

Part Number   Description     
------------- -----------------
CA-14A1       Skillet - 12 Inch 
AZA-52        Roller Skates     
B-9A74        Baseball Bat      

But note that it always inserts a single hyphen, which seems to be what you want; it doesn't separate all groups of characters and numbers (e.g. B9A74 to B-9-A-74). It just puts a hyphen before the first non-alpha character.