MySQL 8.0

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CREATE TABLE mytable (
  val TEXT
);

INSERT INTO mytable VALUES
('Charlie likes fruits. Charlie does not like chocolate.'),
('Today is a good day.  I do not feel like eating chocolate or apples.'),
('1. No chocolate is allowed.'),
('Andy is not a child... He loves chocolate.'),
('Today is not a good day. I have no money. I want to eat chocolate and orange.'), 
('1. Chocolate is good for you.');
SELECT * FROM mytable;


val


Charlie likes fruits. Charlie does not like chocolate.

Today is a good day.  I do not feel like eating chocolate or apples.

1. No chocolate is allowed.

Andy is not a child... He loves chocolate.

Today is not a good day. I have no money. I want to eat chocolate and orange.

1. Chocolate is good for you.


SELECT val,
       SUBSTRING_INDEX(val,'.',2) AS valCheck
FROM mytable
HAVING valCheck LIKE '%chocolate%'


val
valCheck


Charlie likes fruits. Charlie does not like chocolate.
Charlie likes fruits. Charlie does not like chocolate

Today is a good day.  I do not feel like eating chocolate or apples.
Today is a good day.  I do not feel like eating chocolate or apples

1. No chocolate is allowed.
1. No chocolate is allowed

1. Chocolate is good for you.
1. Chocolate is good for you


SELECT * 
FROM
(SELECT val,
       SUBSTRING_INDEX(val,'.',2) AS valCheck
FROM mytable
HAVING valCheck LIKE '%chocolate%') A
WHERE CASE WHEN SUBSTRING_INDEX(valCheck,'chocolate',1) LIKE '%no %' THEN 1
         WHEN SUBSTRING_INDEX(valCheck,'chocolate',1) LIKE '%not %' THEN 1
         ELSE 0 END=1;


val
valCheck


Charlie likes fruits. Charlie does not like chocolate.
Charlie likes fruits. Charlie does not like chocolate

Today is a good day.  I do not feel like eating chocolate or apples.
Today is a good day.  I do not feel like eating chocolate or apples

1. No chocolate is allowed.
1. No chocolate is allowed

val	valCheck
Charlie likes fruits. Charlie does not like chocolate.	Charlie likes fruits. Charlie does not like chocolate
Today is a good day. I do not feel like eating chocolate or apples.	Today is a good day. I do not feel like eating chocolate or apples
1. No chocolate is allowed.	1. No chocolate is allowed
1. Chocolate is good for you.	1. Chocolate is good for you