Defining arrays and objects directly in SQL statement is currently not supported by our SQL parser, please use parameter substitution using placeholders instead as described here: https://crate.io/docs/current/sql/rest.html
Example using curl is as below:
curl -sSXPOST '127.0.0.1:4200/_sql?pretty' -d@- <<- EOF
{"stmt": "update poll set poll_rating = ? where poll_id = ?",
"args": [ [{"rating_id":1,"fk_user_id":-1,"israted_image1":1,"israted_image2":0,"createddate":1400067339.0496}], "f748771d7c2e4616b1865f37b7913707" ]
}
EOF