Db2 Developer-C 11.1

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SELECT JSON_OBJECT(KEY 'x' 
                    VALUE 1)
FROM sysibmadm.env_inst_info
SELECT JSON_OBJECT(KEY 'x' 
                    VALUE (SELECT 1 AS myscalar FROM sysibmadm.env_inst_info))
FROM sysibmadm.env_inst_info 
[IBM][CLI Driver][DB2/LINUXX8664] SQL0104N  An unexpected token ")" was found following "bmadm.env_inst_info)".  Expected tokens may include:  "<interval_qualifier>".  SQLSTATE=42601 SQLCODE=-104

SELECT JSON_OBJECT(KEY 'x' 
                    VALUE myscalar)
FROM sysibmadm.env_inst_info, LATERAL (SELECT 1 AS myscalar FROM sysibmadm.env_inst_info)