diff options
author | Mingdong Luo <mdluo@nsmss.com> | 2015-01-31 19:23:48 -0800 |
---|---|---|
committer | Mingdong Luo <mdluo@nsmss.com> | 2015-01-31 19:23:48 -0800 |
commit | 549d171a90135999e3c670f489494b7a39dd6dd7 (patch) | |
tree | 233466527b797fe3ea7c6a7a3673795cea28aebe /activerecord/lib/active_record/relation/where_clause.rb | |
parent | c840b18ac31a852d99ff760229f2c087b6961727 (diff) | |
parent | 70ac072976c8cc6f013f0df3777e54ccae3f4f8c (diff) | |
download | rails-549d171a90135999e3c670f489494b7a39dd6dd7.tar.gz rails-549d171a90135999e3c670f489494b7a39dd6dd7.tar.bz2 rails-549d171a90135999e3c670f489494b7a39dd6dd7.zip |
Merge branch 'master' into pr/18316
Conflicts:
activerecord/CHANGELOG.md
Diffstat (limited to 'activerecord/lib/active_record/relation/where_clause.rb')
-rw-r--r-- | activerecord/lib/active_record/relation/where_clause.rb | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/relation/where_clause.rb b/activerecord/lib/active_record/relation/where_clause.rb new file mode 100644 index 0000000000..f9b9e640ec --- /dev/null +++ b/activerecord/lib/active_record/relation/where_clause.rb @@ -0,0 +1,173 @@ +module ActiveRecord + class Relation + class WhereClause # :nodoc: + attr_reader :binds + + delegate :any?, :empty?, to: :predicates + + def initialize(predicates, binds) + @predicates = predicates + @binds = binds + end + + def +(other) + WhereClause.new( + predicates + other.predicates, + binds + other.binds, + ) + end + + def merge(other) + WhereClause.new( + predicates_unreferenced_by(other) + other.predicates, + non_conflicting_binds(other) + other.binds, + ) + end + + def except(*columns) + WhereClause.new( + predicates_except(columns), + binds_except(columns), + ) + end + + def or(other) + if empty? + self + elsif other.empty? + other + else + WhereClause.new( + [ast.or(other.ast)], + binds + other.binds + ) + end + end + + def to_h(table_name = nil) + equalities = predicates.grep(Arel::Nodes::Equality) + if table_name + equalities = equalities.select do |node| + node.left.relation.name == table_name + end + end + + binds = self.binds.map { |attr| [attr.name, attr.value] }.to_h + + equalities.map { |node| + name = node.left.name + [name, binds.fetch(name.to_s) { + case node.right + when Array then node.right.map(&:val) + when Arel::Nodes::Casted, Arel::Nodes::Quoted + node.right.val + end + }] + }.to_h + end + + def ast + Arel::Nodes::And.new(predicates_with_wrapped_sql_literals) + end + + def ==(other) + other.is_a?(WhereClause) && + predicates == other.predicates && + binds == other.binds + end + + def invert + WhereClause.new(inverted_predicates, binds) + end + + def self.empty + new([], []) + end + + protected + + attr_reader :predicates + + def referenced_columns + @referenced_columns ||= begin + equality_nodes = predicates.select { |n| equality_node?(n) } + Set.new(equality_nodes, &:left) + end + end + + private + + def predicates_unreferenced_by(other) + predicates.reject do |n| + equality_node?(n) && other.referenced_columns.include?(n.left) + end + end + + def equality_node?(node) + node.respond_to?(:operator) && node.operator == :== + end + + def non_conflicting_binds(other) + conflicts = referenced_columns & other.referenced_columns + conflicts.map! { |node| node.name.to_s } + binds.reject { |attr| conflicts.include?(attr.name) } + end + + def inverted_predicates + predicates.map { |node| invert_predicate(node) } + end + + def invert_predicate(node) + case node + when NilClass + raise ArgumentError, 'Invalid argument for .where.not(), got nil.' + when Arel::Nodes::In + Arel::Nodes::NotIn.new(node.left, node.right) + when Arel::Nodes::Equality + Arel::Nodes::NotEqual.new(node.left, node.right) + when String + Arel::Nodes::Not.new(Arel::Nodes::SqlLiteral.new(node)) + else + Arel::Nodes::Not.new(node) + end + end + + def predicates_except(columns) + predicates.reject do |node| + case node + when Arel::Nodes::Between, Arel::Nodes::In, Arel::Nodes::NotIn, Arel::Nodes::Equality, Arel::Nodes::NotEqual, Arel::Nodes::LessThanOrEqual, Arel::Nodes::GreaterThanOrEqual + subrelation = (node.left.kind_of?(Arel::Attributes::Attribute) ? node.left : node.right) + columns.include?(subrelation.name.to_s) + end + end + end + + def binds_except(columns) + binds.reject do |attr| + columns.include?(attr.name) + end + end + + def predicates_with_wrapped_sql_literals + non_empty_predicates.map do |node| + if Arel::Nodes::Equality === node + node + else + wrap_sql_literal(node) + end + end + end + + def non_empty_predicates + predicates - [''] + end + + def wrap_sql_literal(node) + if ::String === node + node = Arel.sql(node) + end + Arel::Nodes::Grouping.new(node) + end + end + end +end |