class ConceptQL::Operators::TrimDateEnd
Trims the end_date of the LHS set of results by the RHS's earliest start_date (per person) If a the RHS contains a start_date that comes before the LHS's start_date that LHS result is completely discarded.
If there is no RHS result for an LHS result, the LHS result is passed thru unaffected.
If the RHS result's start_date is later than the LHS end_date, the LHS result is passed thru unaffected.
Public Instance Methods
query(db)
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# File lib/conceptql/operators/trim_date_end.rb, line 33 def query(db) grouped_right = db.from(right_stream(db)).select_group(:person_id).select_append(Sequel.as(Sequel.function(:min, :start_date), :start_date)) where_criteria = Sequel.expr { l__start_date <= r__start_date } where_criteria = where_criteria.|(r__start_date: nil) # If the RHS's min start date is less than the LHS start date, # the entire LHS date range is truncated, which implies the row itself # is ineligible to pass thru ds = db.from(left_stream(db)) .left_join(Sequel.as(grouped_right, :r), l__person_id: :r__person_id) .where(where_criteria) .select(*new_columns) .select_append(Sequel.as(Sequel.function(:least, :l__end_date, :r__start_date), :end_date)) ds = add_option_conditions(ds) ds.from_self end
within_column()
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# File lib/conceptql/operators/trim_date_end.rb, line 52 def within_column :l__end_date end
Private Instance Methods
new_columns()
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# File lib/conceptql/operators/trim_date_end.rb, line 57 def new_columns (dynamic_columns - [:end_date]).map { |col| "l__#{col}".to_sym } end