If you don’t use the correct string of predicates in RethinkDB, you can get an error like this:<\/p>\n
Server error:<\/p>\n
e: Cannot convert NUMBER to SEQUENCE in:\nr.db(\"test\").table(\"users\").filter(function(var_229) { return var_229(\"user_name\").match(\"test \"); }).group(\"first_name\").count().map({\"first_name\": r.row(\"group\"), \"val\": r.row(\"reduction\")})\n^^^^^^^<\/pre>\nHere is an example of a query that causes this:<\/p>\n
r.db('test')\n .table('users')\n .filter( (x) => x('user_name').match('test ') )\n .group('first_name')\n .count()\n .map({ first_name: r.row('group'), val: r.row('reduction') })\n<\/pre>\nThe problem with this query is that the output of the grouped “count” is not the same datatype as a regular table. To convert it back, you need to add an additional “ungroup”:<\/p>\n
r.db('test')\n .table('users')\n .filter( (x) => x('user_name').match('test ') )\n .group('first_name')\n .count()\n .ungroup()\n .map(\n { \n first_name: r.row('group'),\n val: r.row('reduction') \n })\n<\/pre>\n","protected":false},"excerpt":{"rendered":"If you don’t use the correct string of predicates in RethinkDB, you can get an error like this: Server error: e: Cannot convert NUMBER to SEQUENCE in: r.db(“test”).table(“users”).filter(function(var_229) { return var_229(“user_name”).match(“test “); }).group(“first_name”).count().map({“first_name”: r.row(“group”), “val”: r.row(“reduction”)}) ^^^^^^^ Here is an example of a query that causes this: r.db(‘test’) .table(‘users’) .filter( (x) => x(‘user_name’).match(‘test ‘) ) … <\/p>\n