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CREATE TABLE mytable(
js json NOT NULL
,id INTEGER NOT NULL
);
INSERT INTO mytable(js,id) VALUES ('{"feature": 1}',123);
INSERT INTO mytable(js,id) VALUES ('{"features": 2}',223);
INSERT INTO mytable(js,id) VALUES ('{"feature": 3}',323);
INSERT INTO mytable(js,id) VALUES ('{"features": 4}',423);
select coalesce(js ->> '$.feature', js ->> '$.features') feature, id
from mytable
| feature | id |
|---|---|
| 1 | 123 |
| 2 | 223 |
| 3 | 323 |
| 4 | 423 |