SQL subtracting a string column from another string column - sql

Question

I am looking to subtract two string columns from another string column.
I have acheived this in the past in Oracle using the below
SELECT
C.MANUFACTURER,
C.MODEL_GROUP,
REGEXP_REPLACE(C.VARIANT, '^'||C.MANUFACTURER || ' +' || C.MODEL_GROUP) "VAR DESC",
C.VARIANT
FROM STD_BI.RL2_CONTRACTS_VW C
I now need to acheive the same in MS SQL any suggestions would be appreciated.

Answer 1

"Subtract" is surely a misnomer here. The OP appears to want to remove a string at the beginning of another string.
From this point on, I am assuming that MANUFACTURER and MODEL_GROUP do not contain any regular expression wildcard characters.
There is a challenge with multiple spaces. If there are not too many, then you can do. For instance, this handles one or two spaces:
SELECT C.MANUFACTURER, C.MODEL_GROUP,
(CASE WHEN C.VARIANT LIKE C.MANUFACTURER + ' ' + C.MODEL_GROUP + '%'
THEN STUFF(C.VARIANT, 1, LEN(C.MANUFACTURER + ' ' + C.MODEL_GROUP), '')
WHEN C.VARIANT LIKE C.MANUFACTURER + ' ' + C.MODEL_GROUP + '%' AND
THEN STUFF(C.VARIANT, 1, LEN(C.MANUFACTURER + ' ' + C.MODEL_GROUP), '')
ELSE C.VARIANT
END) as [VAR DESC],
C.VARIANT
FROM STD_BI.RL2_CONTRACTS_VW C;
EDIT:
Here is a more complete solution:
SELECT C.MANUFACTURER, C.MODEL_GROUP,
(CASE WHEN C.VARIANT LIKE C.MANUFACTURER + ' %' + C.MODEL_GROUP + '%' AND
C.VARIANT NOT LIKE C.MANUFACTURER + ' %[^ ]%' + C.MODEL_GROUP + '%'
THEN STUFF(LTRIM(STUFF(C.VARIANT, 1, LEN(C.MANUFACTURER), '')), 1, LEN(C.MODEL_GROUP), '')
ELSE C.VARIANT
END) as [VAR DESC],
C.VARIANT
FROM STD_BI.RL2_CONTRACTS_VW C;
This tests for just spaces between the two strings (the not like is checking for something other than a space). The replacement is then in three steps -- remove the manufacturer, then the spaces, then the model group.

Answer 2

I have spent some time on this one as much for my own satisfaction and in addition to the answer above, I have come up with the following which also generates the correct answer.
SUBSTRING(FV.VARIANT, LEN(FV.MANUFACTURER + ' ' + FV.MODEL_RANGE + ' ') + 1 , LEN(FV.VARIANT))

Answer 3

My problem was kinda easier to solve, I just needed to remove "xxxx" (the first 4 characters) at the start of a column from some rows:
UPDATE coluna SET columToEdit = SUBSTRING(columToEdit, 5, 200);