Open lisette-bouwmeester1 opened 2 years ago
Considering this example collection:
students <- mongo("students") students$insert(c( '{ "student" : 1, "grades" : [ 95, 92, 90 ] }', '{ "student" : 2, "grades" : [ 98, 100, 102 ] }', '{ "student" : 3, "grades" : [ 95, 110, 100] }'))
I am trying to get from all documents the first element in grade. I tried the following, but this gives as output NULL
students$find(query = '{}', fields = '{"grades.0" : true}')
Why doesn't this work in the field operator, as it does work in the query part when looking for the student with the first grade 98:
students$find(query = '{"grades.0" : 98}', fields = '{"student" : true}')
I don't understand what I do wrong. Thanks for your help!
Considering this example collection:
students <- mongo("students") students$insert(c( '{ "student" : 1, "grades" : [ 95, 92, 90 ] }', '{ "student" : 2, "grades" : [ 98, 100, 102 ] }', '{ "student" : 3, "grades" : [ 95, 110, 100] }'))I am trying to get from all documents the first element in grade. I tried the following, but this gives as output NULL
students$find(query = '{}', fields = '{"grades.0" : true}')Why doesn't this work in the field operator, as it does work in the query part when looking for the student with the first grade 98:
students$find(query = '{"grades.0" : 98}', fields = '{"student" : true}')I don't understand what I do wrong. Thanks for your help!