class Arel::SelectManager - arel-4.0.2 Documentation

# class Arel::SelectManager

### Public Class Methods

new(engine, table = nil) click to toggle source
Calls superclass method Arel::TreeManager.new

    # File lib/arel/select_manager.rb, line 5
    def initialize engine, table = nil
      super(engine)
      @ast   = Nodes::SelectStatement.new
      @ctx    = @ast.cores.last
      from table
    end

### Public Instance Methods

as(other) click to toggle source

    # File lib/arel/select_manager.rb, line 46
    def as other
      create_table_alias grouping(@ast), Nodes::SqlLiteral.new(other)
    end

constraints() click to toggle source

    # File lib/arel/select_manager.rb, line 22
    def constraints
      @ctx.wheres
    end

distinct(value = true) click to toggle source

    # File lib/arel/select_manager.rb, line 152
    def distinct(value = true)
      if value
        @ctx.set_quantifier = Arel::Nodes::Distinct.new
      else
        @ctx.set_quantifier = nil
      end
    end

except(other) click to toggle source

    # File lib/arel/select_manager.rb, line 199
    def except other
      Nodes::Except.new ast, other.ast
    end

Also aliased as: minus
exists() click to toggle source

Produces an Arel::Nodes::Exists node

    # File lib/arel/select_manager.rb, line 42
    def exists
      Arel::Nodes::Exists.new @ast
    end

from(table) click to toggle source

    # File lib/arel/select_manager.rb, line 91
    def from table
      table = Nodes::SqlLiteral.new(table) if String === table
      # FIXME: this is a hack to support
      # test_with_two_tables_in_from_without_getting_double_quoted
      # from the AR tests.

      case table
      when Nodes::Join
        @ctx.source.right << table
      else
        @ctx.source.left = table
      end

      self
    end

froms() click to toggle source

    # File lib/arel/select_manager.rb, line 107
    def froms
      @ast.cores.map { |x| x.from }.compact
    end

group(*columns) click to toggle source

    # File lib/arel/select_manager.rb, line 80
    def group *columns
      columns.each do |column|
        # FIXME: backwards compat
        column = Nodes::SqlLiteral.new(column) if String === column
        column = Nodes::SqlLiteral.new(column.to_s) if Symbol === column

        @ctx.groups.push Nodes::Group.new column
      end
      self
    end

having(*exprs) click to toggle source

    # File lib/arel/select_manager.rb, line 124
    def having *exprs
      @ctx.having = Nodes::Having.new(collapse(exprs, @ctx.having))
      self
    end

initialize_copy(other) click to toggle source
Calls superclass method Arel::TreeManager#initialize_copy

    # File lib/arel/select_manager.rb, line 12
    def initialize_copy other
      super
      @ctx = @ast.cores.last
    end

insert(values) click to toggle source

FIXME: this method should go away

    # File lib/arel/select_manager.rb, line 276
        def insert values
          if $VERBOSE
            warn <<-eowarn
    insert (#{caller.first}) is deprecated and will be removed in Arel 4.0.0. Please
    switch to `compile_insert`
            eowarn
          end

          im = compile_insert(values)
          table = @ctx.froms

          primary_key      = table.primary_key
          primary_key_name = primary_key.name if primary_key

          # FIXME: in AR tests values sometimes were Array and not Hash therefore is_a?(Hash) check is added
          primary_key_value = primary_key && values.is_a?(Hash) && values[primary_key]
          im.into table
          # Oracle adapter needs primary key name to generate RETURNING ... INTO ... clause
          # for tables which assign primary key value using trigger.
          # RETURNING ... INTO ... clause will be added only if primary_key_value is nil
          # therefore it is necessary to pass primary key value as well
          @engine.connection.insert im.to_sql, 'AREL', primary_key_name, primary_key_value
        end

intersect(other) click to toggle source

    # File lib/arel/select_manager.rb, line 195
    def intersect other
      Nodes::Intersect.new ast, other.ast
    end

join(relation, klass = Nodes::InnerJoin) click to toggle source

    # File lib/arel/select_manager.rb, line 111
    def join relation, klass = Nodes::InnerJoin
      return self unless relation

      case relation
      when String, Nodes::SqlLiteral
        raise if relation.blank?
        klass = Nodes::StringJoin
      end

      @ctx.source.right << create_join(relation, nil, klass)
      self
    end

join_sources() click to toggle source

    # File lib/arel/select_manager.rb, line 241
    def join_sources
      @ctx.source.right
    end

join_sql() click to toggle source

    # File lib/arel/select_manager.rb, line 227
    def join_sql
      return nil if @ctx.source.right.empty?

      sql = visitor.dup.extend(Visitors::JoinSql).accept @ctx
      Nodes::SqlLiteral.new sql
    end

joins(manager) click to toggle source

    # File lib/arel/select_manager.rb, line 249
    def joins manager
      if $VERBOSE
        warn "joins is deprecated and will be removed in 4.0.0"
        warn "please remove your call to joins from #{caller.first}"
      end
      manager.join_sql
    end

limit() click to toggle source

    # File lib/arel/select_manager.rb, line 17
    def limit
      @ast.limit && @ast.limit.expr
    end

Also aliased as: taken
limit=(limit)
Alias for: take
lock(locking = Arel.sql('FOR UPDATE')) click to toggle source

    # File lib/arel/select_manager.rb, line 58
    def lock locking = Arel.sql('FOR UPDATE')
      case locking
      when true
        locking = Arel.sql('FOR UPDATE')
      when Arel::Nodes::SqlLiteral
      when String
        locking = Arel.sql locking
      end

      @ast.lock = Nodes::Lock.new(locking)
      self
    end

locked() click to toggle source

    # File lib/arel/select_manager.rb, line 71
    def locked
      @ast.lock
    end

minus(other)
Alias for: except
offset() click to toggle source

    # File lib/arel/select_manager.rb, line 26
    def offset
      @ast.offset && @ast.offset.expr
    end

offset=(amount)
Alias for: skip
on(*exprs) click to toggle source

    # File lib/arel/select_manager.rb, line 75
    def on *exprs
      @ctx.source.right.last.right = Nodes::On.new(collapse(exprs))
      self
    end

order(*expr) click to toggle source

    # File lib/arel/select_manager.rb, line 160
    def order *expr
      # FIXME: We SHOULD NOT be converting these to SqlLiteral automatically
      @ast.orders.concat expr.map { |x|
        String === x || Symbol === x ? Nodes::SqlLiteral.new(x.to_s) : x
      }
      self
    end

order_clauses() click to toggle source

    # File lib/arel/select_manager.rb, line 234
    def order_clauses
      visitor = Visitors::OrderClauses.new(@engine.connection)
      visitor.accept(@ast).map { |x|
        Nodes::SqlLiteral.new x
      }
    end

orders() click to toggle source

    # File lib/arel/select_manager.rb, line 168
    def orders
      @ast.orders
    end

project(*projections) click to toggle source

    # File lib/arel/select_manager.rb, line 135
    def project *projections
      # FIXME: converting these to SQLLiterals is probably not good, but
      # rails tests require it.
      @ctx.projections.concat projections.map { |x|
        [Symbol, String].include?(x.class) ? SqlLiteral.new(x.to_s) : x
      }
      self
    end

projections() click to toggle source

    # File lib/arel/select_manager.rb, line 144
    def projections
      @ctx.projections
    end

projections=(projections) click to toggle source

    # File lib/arel/select_manager.rb, line 148
    def projections= projections
      @ctx.projections = projections
    end

skip(amount) click to toggle source

    # File lib/arel/select_manager.rb, line 30
    def skip amount
      if amount
        @ast.offset = Nodes::Offset.new(amount)
      else
        @ast.offset = nil
      end
      self
    end

Also aliased as: offset=
source() click to toggle source

    # File lib/arel/select_manager.rb, line 245
    def source
      @ctx.source
    end

take(limit) click to toggle source

    # File lib/arel/select_manager.rb, line 215
    def take limit
      if limit
        @ast.limit = Nodes::Limit.new(limit)
        @ctx.top   = Nodes::Top.new(limit)
      else
        @ast.limit = nil
        @ctx.top   = nil
      end
      self
    end

Also aliased as: limit=
taken()
Alias for: limit
union(operation, other = nil) click to toggle source

    # File lib/arel/select_manager.rb, line 184
    def union operation, other = nil
      if other
        node_class = Nodes.const_get("Union#{operation.to_s.capitalize}")
      else
        other = operation
        node_class = Nodes::Union
      end

      node_class.new self.ast, other.ast
    end

where_clauses() click to toggle source

    # File lib/arel/select_manager.rb, line 50
    def where_clauses
      if $VERBOSE
        warn "(#{caller.first}) where_clauses is deprecated and will be removed in arel 4.0.0 with no replacement"
      end
      to_sql = Visitors::ToSql.new @engine.connection
      @ctx.wheres.map { |c| to_sql.accept c }
    end

where_sql() click to toggle source

    # File lib/arel/select_manager.rb, line 177
    def where_sql
      return if @ctx.wheres.empty?

      viz = Visitors::WhereSql.new @engine.connection
      Nodes::SqlLiteral.new viz.accept @ctx
    end

wheres() click to toggle source

    # File lib/arel/select_manager.rb, line 172
    def wheres
      warn "#{caller[0]}: SelectManager#wheres is deprecated and will be removed in Arel 4.0.0 with no replacement"
      Compatibility::Wheres.new @engine.connection, @ctx.wheres
    end

window(name) click to toggle source

    # File lib/arel/select_manager.rb, line 129
    def window name
      window = Nodes::NamedWindow.new(name)
      @ctx.windows.push window
      window
    end

with(*subqueries) click to toggle source

    # File lib/arel/select_manager.rb, line 204
    def with *subqueries
      if subqueries.first.is_a? Symbol
        node_class = Nodes.const_get("With#{subqueries.shift.to_s.capitalize}")
      else
        node_class = Nodes::With
      end
      @ast.with = node_class.new(subqueries.flatten)

      self
    end

### Private Instance Methods

collapse(exprs, existing = nil) click to toggle source

    # File lib/arel/select_manager.rb, line 301
    def collapse exprs, existing = nil
      exprs = exprs.unshift(existing.expr) if existing
      exprs = exprs.compact.map { |expr|
        if String === expr
          # FIXME: Don't do this automatically
          Arel.sql(expr)
        else
          expr
        end
      }

      if exprs.length == 1
        exprs.first
      else
        create_and exprs
      end
    end