SQL Server 2017 (Linux)

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SET NOCOUNT ON;
CREATE TABLE TEST_CASES(
  INGS NVARCHAR(MAX),
  REQ NVARCHAR(MAX),
  XR INT
);
INSERT INTO TEST_CASES(INGS, REQ, XR) VALUES
  ('spam,spam,spam,spam,bacon,eggs,eggs,bacon,spam','beans', 2),
  ('bacon,bacon,bacon,bacon,bacon', 'bacon', 5),
  ('banana,coconut', 'bacon', 1),
  ('acon,bcon,baon,bacn,baco', 'bacon', 4),
  ('tomato,oregano,pizza,chocolate', 'bacon', 0),
  ('strawberries,figs,chocolate,sardines', 'cod fish', 1),
  ('these,are,some,random,words,wow', 'or', 3),
  ('some,more,delicious,ingredients,here', 'bolognese', 0),
  ('some,delicious,ingredients,here,are,bliss', 'bolognese', 1),
  ('some,bountiful,bagful,of,ingredients,here,are,bliss', 'bolognese', 1);
CREATE FUNCTION F(@ NVARCHAR(MAX),@R NVARCHAR(MAX))RETURNS
TABLE RETURN WITH A AS(SELECT LEFT(@R,1)C,STUFF(@R,1,1,'')R
UNION ALL SELECT LEFT(R,1),STUFF(R,1,1,'')FROM A
WHERE R!=''),B AS(SELECT(LEN(@)-LEN(REPLACE(@,C,'')))/COUNT(*)OVER(PARTITION BY C)R
FROM A WHERE C LIKE'[A-Z]')SELECT MIN(R)R FROM B
SELECT *
FROM TEST_CASES
CROSS APPLY F(INGS,REQ)
OPTION(MAXRECURSION 0);


INGS
REQ
XR
R


spam,spam,spam,spam,bacon,eggs,eggs,bacon,spam
beans
2
2

bacon,bacon,bacon,bacon,bacon
bacon
5
5

banana,coconut
bacon
1
1

acon,bcon,baon,bacn,baco
bacon
4
4

tomato,oregano,pizza,chocolate
bacon
0
0

strawberries,figs,chocolate,sardines
cod fish
1
1

these,are,some,random,words,wow
or
3
3

some,more,delicious,ingredients,here
bolognese
0
0

some,delicious,ingredients,here,are,bliss
bolognese
1
1

some,bountiful,bagful,of,ingredients,here,are,bliss
bolognese
1
1


ALTER FUNCTION F(@ NVARCHAR(MAX), @R NVARCHAR(MAX)) RETURNS TABLE RETURN
  WITH
    A AS(
      SELECT LEFT(@R, 1) AS C, STUFF(@R, 1, 1, '') AS R
      UNION ALL
      SELECT LEFT(R, 1), STUFF(R, 1, 1, '') FROM A WHERE R != ''
    ),
    B AS(
      SELECT
        (LEN(@) - LEN(REPLACE(@, C, ''))) / COUNT(*) OVER(PARTITION BY C) AS R
      FROM A
      WHERE C LIKE '[A-Z]'
    )
  SELECT MIN(R) AS R FROM B;
SELECT *
FROM TEST_CASES
CROSS APPLY F(INGS,REQ)
OPTION(MAXRECURSION 0);


INGS
REQ
XR
R


spam,spam,spam,spam,bacon,eggs,eggs,bacon,spam
beans
2
2

bacon,bacon,bacon,bacon,bacon
bacon
5
5

banana,coconut
bacon
1
1

acon,bcon,baon,bacn,baco
bacon
4
4

tomato,oregano,pizza,chocolate
bacon
0
0

strawberries,figs,chocolate,sardines
cod fish
1
1

these,are,some,random,words,wow
or
3
3

some,more,delicious,ingredients,here
bolognese
0
0

some,delicious,ingredients,here,are,bliss
bolognese
1
1

some,bountiful,bagful,of,ingredients,here,are,bliss
bolognese
1
1

INGS	REQ	XR	R
spam,spam,spam,spam,bacon,eggs,eggs,bacon,spam	beans	2	2
bacon,bacon,bacon,bacon,bacon	bacon	5	5
banana,coconut	bacon	1	1
acon,bcon,baon,bacn,baco	bacon	4	4
tomato,oregano,pizza,chocolate	bacon	0	0
strawberries,figs,chocolate,sardines	cod fish	1	1
these,are,some,random,words,wow	or	3	3
some,more,delicious,ingredients,here	bolognese	0	0
some,delicious,ingredients,here,are,bliss	bolognese	1	1
some,bountiful,bagful,of,ingredients,here,are,bliss	bolognese	1	1