If you run a RethinkDB query, you can get an error attempting to intersect two tables:<\/p>\n
r.db('test')\n .table('users')\n .filter( (x) => x('user_name').match('test ') )\n .setIntersection(\n r.db('test')\n .table('users')\n .filter(\n (x) => x('user_name').match('9')\n )\n )\n<\/pre>\nThe error looks like so:<\/p>\n
Expected type DATUM but found SELECTION\n<\/pre>\nThe reason you get this error is that you have attempted to intersect two tables, when the function expects two arrays.<\/p>\n
The simplest way to do this is to join the data on it’s IDs.<\/p>\n
r.db('test')\n .table('users')\n .eqJoin(\n 'id',\n r.table('users')\n )\n<\/pre>\nIf you actually want to do this on all columns, you’ll need to implement a more complex filter, that looks at each column.<\/p>\n
You can also get this error if you try to alias columns in the incorrect way:<\/p>\n
\nr.db('test')\n .table('salaries')\n .group('role')\n .avg('salary')\n .ungroup()\n .map({group: 'Title', reduction: 'Amount'})\n<\/pre>\nInstead, you want this:<\/p>\n
\nr.db('test')\n .table('salaries')\n .group('role')\n .avg('salary')\n .ungroup()\n .map({\n group: r.row('Title'), \n reduction: r.row('Amount')\n })\n<\/pre>\n","protected":false},"excerpt":{"rendered":"If you run a RethinkDB query, you can get an error attempting to intersect two tables: r.db(‘test’) .table(‘users’) .filter( (x) => x(‘user_name’).match(‘test ‘) ) .setIntersection( r.db(‘test’) .table(‘users’) .filter( (x) => x(‘user_name’).match(‘9’) ) ) The error looks like so: Expected type DATUM but found SELECTION The reason you get this error is that you have attempted … <\/p>\n