Support JSON type

USE test;

DROP TABLE IF EXISTS tj;

CREATE TABLE tj(j JSON); --ENGINE=COLUMNSTORE;

INSERT INTO tj(j) VALUES ('()'); -- invalid

INSERT INTO tj(j) VALUES ('[]'), ('{}'), ('"a"'); -- valid

SELECT * FROM tj WHERE j = '"A"'; -- empty set.

SELECT * FROM tj WHERE j = '"a"'; -- single row.

INSERT INTO tj(j) VALUES ('{"a":"b", "b":"a"}');

SELECT * FROM tj WHERE j = '{"b":"a","a":"b"}'; -- empty set, comparison is not structural.

UPDATE tj SET j = CONCAT(j,'()');