Db8 substring query

how to use the %% (substring finder) operator in db8 as a query.

while using the command

luna-send -n 1 -f -m com.palm.configurator luna://com.webos.service.db/find '{"query": {"from":"com.webos.chef:1" ,"where":[{"prop":"ingredients","op":"%%","val":"egg"}]}}'

we got the error

"errorCode": 22,
"errorText": "invalid parameters: caller='com.palm.configurator' error='invalid enum value for property 'op' for property 'where' for property 'query''",
"returnValue": false

Use search method with filter clause for sub string matching.

luna-send -n 1 -f -m com.palm.configurator luna://com.webos.service.db/search '{"query": {"from":"com.webos.chef:1" ,"filter":[{"prop":"ingredients","op":"%%","val":"egg"}]}}'