MySQL 5.7

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create table test (rule_condition TEXT)
insert into test values ('{"rule_type":"Member","rule_item":"Rank","rule_operator":"!=","rule_value":"Gold"}'),
('{"rule_type":"Member","rule_item":"Rank","rule_operator":"=","rule_value":"Platinum"}')

Records: 2  Duplicates: 0  Warnings: 0


set @rankName := CAST("Gold" AS CHAR CHARACTER SET utf8mb4)
SELECT rule_condition
FROM test
WHERE rule_condition->>'$.rule_item' = 'Rank'
  AND (rule_condition->>'$.rule_operator' = '!=' AND rule_condition->>'$.rule_value' != @rankName
    OR rule_condition->>'$.rule_operator' = '=' AND rule_condition->>'$.rule_value' = @rankName)


rule_condition


set @rankName := CAST("Silver" AS CHAR CHARACTER SET utf8mb4)
SELECT rule_condition
FROM test
WHERE rule_condition->>'$.rule_item' = 'Rank'
  AND (rule_condition->>'$.rule_operator' = '!=' AND rule_condition->>'$.rule_value' != @rankName
    OR rule_condition->>'$.rule_operator' = '=' AND rule_condition->>'$.rule_value' = @rankName)


rule_condition


{"rule_type":"Member","rule_item":"Rank","rule_operator":"!=","rule_value":"Gold"}


set @rankName := CAST("Platinum" AS CHAR CHARACTER SET utf8mb4)
SELECT rule_condition
FROM test
WHERE rule_condition->>'$.rule_item' = 'Rank'
  AND (rule_condition->>'$.rule_operator' = '!=' AND rule_condition->>'$.rule_value' != @rankName
    OR rule_condition->>'$.rule_operator' = '=' AND rule_condition->>'$.rule_value' = @rankName)


rule_condition


{"rule_type":"Member","rule_item":"Rank","rule_operator":"!=","rule_value":"Gold"}

{"rule_type":"Member","rule_item":"Rank","rule_operator":"=","rule_value":"Platinum"}