SQLite 3.27

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CREATE TABLE tablename(Company_name_ TEXT);
✓
INSERT INTO tablename(Company_name_) VALUES
  ('Example LLC $42'),
  ('Example llc,klp'),
  ('Example LLc jim'),
  ('Example jack');
✓
SELECT CASE
         WHEN Company_name_ LIKE '%LLC%'
           THEN SUBSTR(
                  Company_name_,
                  1,
                  INSTR(UPPER(Company_name_), 'LLC') + LENGTH('LLC') - 1
                ) 
         ELSE Company_name_ 
       END Company_name_   
FROM tablename;


Company_name_


Example LLC

Example llc

Example LLc

Example jack


UPDATE tablename
SET Company_name_ = SUBSTR(
                      Company_name_,
                      1,
                      INSTR(UPPER(Company_name_), 'LLC') + LENGTH('LLC') - 1
                    ) 
WHERE Company_name_ LIKE '%LLC%';
✓
SELECT * FROM tablename;


Company_name_


Example LLC

Example llc

Example LLc

Example jack