Sha256: 8f0b25b59f323fb2324c6383527496c2eea172826bd195850d586bd52c94603a
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Versions: 13
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Stored size: 1.82 KB
Contents
class Card
module Query
class SqlStatement
# transform joins from Card::Query::Join objects to SQL string clause
module Joins
def joins query=nil
query ||= @query
joins_on_query(query).map do |join|
join_clause join
end.flatten.join " "
end
def joins_on_query query
query.direct_subqueries.unshift(query).map(&:joins).flatten
end
def join_clause join
subclause = subjoins join
table = join_table join
on = on_clause join
join_clause_parts(join, table, subclause, on).compact.join " "
end
def join_clause_parts join, table, subclause, on
parts = ["\n#{leading_space}", join.side, "JOIN"]
if join.left? && subclause.present?
parts + ["(#{table} #{subclause})", on]
else
parts + [table, on, subclause]
end
end
def subjoins join
return unless join.to.is_a? AbstractQuery
joins join.to
end
def join_table join
to_table = join.to_table
to_table = "(#{to_table.sql})" if to_table.is_a? CardQuery
[to_table, join.to_alias].join " "
end
def on_clause join
on_conditions = join.conditions
on_conditions.unshift ["#{join.from_alias}.#{join.from_field}",
"#{join.to_alias}.#{join.to_field}"].join(" = ")
on_conditions += on_card_conditions(join) if join.to.is_a? CardQuery
"ON #{basic_conditions(on_conditions) * ' AND '}"
end
def on_card_conditions join
to = join.to
explicit = to.conditions_on_join == join ? explicit_conditions(to) : nil
[explicit, implicit_conditions(to)].compact
end
end
end
end
end
Version data entries
13 entries across 13 versions & 1 rubygems