I think it is safer to mention that the -> operator is *incompatible* with MySQL and Postgres' version of ->. In MySQL and Postgres, the only reason why you would use -> is to get a JSON quoted string, which no SQLite json function supports. Instead, it is only when using the ->> operator that behaviour between SQLite and MySQL or SQLite and Postgres are semantically identical.
```
# Postgres and SQLite
-- for valid inputs, '->' is not compatible
postgres> SELECT '{"a":{"b":{"c":"value"}}}'::JSON->'a'->'b'->'c';
"value"
sqlite> SELECT '{"a":{"b":{"c":"value"}}}'->'a'->'b'->'c';
value
-- for valid inputs, '->>' is compatible
postgres> SELECT '{"a":{"b":{"c":"value"}}}'::JSON->'a'->'b'->>'c';
value
sqlite> SELECT '{"a":{"b":{"c":"value"}}}'->'a'->'b'->>'c';
value
-- for invalid inputs, '->' is not compatible
postgres> SELECT '{"a":{"b":{"c":"value'::JSON->'a'->'b'->'c';
ERROR: invalid input syntax for type json
sqlite> SELECT '{"a":{"b":{"c":"value'->'a'->'b'->'c'; -- json_nextract cascades NULL all the way down the chain
NULL
-- for invalid inputs, '->>' is compatible
postgres> SELECT '{"a":{"b":{"c":"value'::JSON->'a'->'b'->>'c';
ERROR: invalid input syntax for type json
sqlite> SELECT '{"a":{"b":{"c":"value'->'a'->'b'->>'c'; -- json_nextract cascades NULL, but gets caught by the json_extract at the end of the chain
malformed JSON
```
```
# MySQL and SQLite
# I'm using json_extract() and json_unquote(json_extract()) as aliases for -> and ->> because no db fiddle website I found seems to support that syntax for MySQL
-- for valid inputs, '->' is not compatible
mysql> SELECT json_extract('{"a":{"b":{"c":"value"}}}', '$.a.b.c');
"value"
sqlite> SELECT '{"a":{"b":{"c":"value"}}}'->'$.a.b.c';
value
-- for valid inputs, '->>' is compatible
mysql> SELECT json_unquote(json_extract('{"a":{"b":{"c":"value"}}}', '$.a.b.c'));
value
sqlite> SELECT '{"a":{"b":{"c":"value"}}}'->>'$.a.b.c';
value
-- for invalid inputs, '->' is not compatible
mysql> SELECT json_extract('{"a":{"b":{"c":"value', '$.a.b.c');
Error: ER_INVALID_JSON_TEXT_IN_PARAM
sqlite> SELECT '{"a":{"b":{"c":"value'->'$.a.b.c'; -- json_nextract cascades NULL all the way down the chain
NULL
-- for invalid inputs, '->>' is compatible
mysql> SELECT json_unquote(json_extract('{"a":{"b":{"c":"value', '$.a.b.c'));
Error: ER_INVALID_JSON_TEXT_IN_PARAM
sqlite> SELECT '{"a":{"b":{"c":"value'->>'$.a.b.c'; -- json_extract catches the error
malformed JSON
```