Actual DialPlan:

exten => 1111,3,MYSQL(Query resultid ${connid} SELECT\ conf_room_id\ from\ cst_conf_rooms\ where\ conf_room_id=${CON_ID})
exten => 1111,4,MYSQL(Fetch fetchid ${resultid} CONRM)
exten => 1111,5,MeetMe(${CONRM},,12345)
exten => 1111,6,MYSQL(Clear ${resultid})
exten => 1111,7,MYSQL(Disconnect ${connid})


Result:

    -- Executing MYSQL("SIP/203-eebf", "Query resultid 19 SELECT conf_room_id from cst_conf_rooms where conf_room_id=10000") in new stack
    -- Executing MYSQL("SIP/203-eebf", "Fetch fetchid 20 CONRM") in new stack
    -- Executing MeetMe("SIP/203-eebf", "10000||12345") in new stack
  == Parsing '/etc/asterisk/meetme.conf': Found
    -- Created MeetMe conference 1023 for conference '10000'
    -- Playing 'conf-onlyperson' (language 'en')