grouped method
Transforms this join query result to a nested data structure. For example,
a join between teachers and students normally returns a result of the
form:
{ teacher: {name: 'Mr. Smith'}, student: {name: 'John Doe'} },
{ teacher: {name: 'Mr. Smith'}, student: {name: 'Jane Smith'} },
{ teacher: {name: 'Mr. EmptyClass'}, student: undefined },
into a result of the form:
[
{ teacher: {name: 'Mr. Smith'}, students:
{ name: 'John Doe' },
{ name: 'Jane Smith' },
},
{ teacher: {name: 'Mr. EmptyClass'}, students: [] },
]
Implementation
@override
GroupedJoin grouped() => GroupedJoin._(this);