MySQL 8.0

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CREATE TABLE trial7 (
  Name TEXT NULL , 
  Age INT NULL , 
  BPsystolic INT NULL , 
  BPdiastolic INT NULL , 
  ClinicalFeaturesOfTheTIA TEXT NULL , 
  DurationOfSymptoms INT NULL , 
  HistoryOfDiabetes TEXT NULL , 
  ABCD²ScoreForTIA FLOAT NULL 
);

INSERT INTO trial7 (Name, Age, BPsystolic, BPdiastolic, ClinicalFeaturesOfTheTia, DurationOfSymptoms, HistoryOfDiabetes, ABCD²ScoreForTIA) VALUES 
  ('Person A', '71', '137', '85', 'Speech disturbance without weakness', '17', 'Yes', null),
  ('Person B', '92', '125', '78', 'Other symptoms', '43', 'Yes', null),
  ('Person C', '27', '130', '90', 'Other symptoms', '34', 'No', null);
UPDATE trial7 
SET ABCD²ScoreForTIA = (
  (Age >= 60) + (BPsystolic >= 140) + (BPdiastolic >= 90) + 
  (
    case ClinicalFeaturesOfTheTia
       when 'Unilateral weakness' then 2 
       when 'Speech disturbance without weakness' then 1 
       when 'Other symptoms' then 0 
     end
  ) + 
  (
    case 
      when DurationOfSymptoms >= 60 then 2 
      when DurationOfSymptoms >= 10 then 1 
      when DurationOfSymptoms < 10 then 0 
    end
  ) + 
  (HistoryOfDiabetes = 'Yes')
) / 8 
WHERE ABCD²ScoreForTIA IS NULL
SELECT * FROM trial7


Name
Age
BPsystolic
BPdiastolic
ClinicalFeaturesOfTheTIA
DurationOfSymptoms
HistoryOfDiabetes
ABCD²ScoreForTIA


Person A
71
137
85
Speech disturbance without weakness
17
Yes
0.5

Person B
92
125
78
Other symptoms
43
Yes
0.375

Person C
27
130
90
Other symptoms
34
No
0.25

Name	Age	BPsystolic	BPdiastolic	ClinicalFeaturesOfTheTIA	DurationOfSymptoms	HistoryOfDiabetes	ABCD²ScoreForTIA
Person A	71	137	85	Speech disturbance without weakness	17	Yes	0.5
Person B	92	125	78	Other symptoms	43	Yes	0.375
Person C	27	130	90	Other symptoms	34	No	0.25