Class: Arel::SelectManager

Inherits:
TreeManager show all
Includes:
Crud
Defined in:
lib/arel/select_manager.rb

Defined Under Namespace

Classes: Row

Instance Attribute Summary

Attributes inherited from TreeManager

#ast, #engine, #visitor

Instance Method Summary collapse

Methods included from Crud

#delete, #update

Methods inherited from TreeManager

#initialize_copy, #to_dot, #to_sql, #where

Constructor Details

#initialize(engine, table = nil) ⇒ SelectManager

Returns a new instance of SelectManager.



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# 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

Instance Method Details

#constraints ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 16

def constraints
  @ctx.wheres
end

#except(other) ⇒ Object Also known as: minus 



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# File 'lib/arel/select_manager.rb', line 154

def except other
  Nodes::Except.new ast, other.ast
end

#exists ⇒ Object

Produces an Arel::Nodes::Exists node



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# File 'lib/arel/select_manager.rb', line 27

def exists
  Arel::Nodes::Exists.new @ast
end

#from(table) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 70

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.
  if @ctx.froms
    source = @ctx.froms

    if Nodes::SqlLiteral === table && Nodes::Join === source
      source.left = table
      table = source
    end
  end

  @ctx.froms = table
  self
end

#group(*columns) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 59

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(expr) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 100

def having expr
  expr = Nodes::SqlLiteral.new(expr) if String === expr

  @ctx.having = Nodes::Having.new(expr)
  self
end

#insert(values) ⇒ Object

FIXME: this method should go away



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# File 'lib/arel/select_manager.rb', line 205

def insert values
  im = InsertManager.new @engine
  table = @ctx.froms
  primary_key_name = (primary_key = table.primary_key) && primary_key.name
  # 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
  im.insert values
  # 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) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 150

def intersect other
  Nodes::Intersect.new ast, other.ast
end

#join(relation, klass = Nodes::InnerJoin) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 88

def join relation, klass = Nodes::InnerJoin
  return self unless relation

  case relation
  when String, Nodes::SqlLiteral
    raise if relation.blank?
    from Nodes::StringJoin.new(@ctx.froms, relation)
  else
    from klass.new(@ctx.froms, relation, nil)
  end
end

#join_sql ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 165

def join_sql
  return nil unless @ctx.froms

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

#joins(manager) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 178

def joins manager
  if $VERBOSE
    warn "joins is deprecated and will be removed in 2.2"
    warn "please remove your call to joins from #{caller.first}"
  end
  manager.join_sql
end

#lock(locking = Arel.sql('FOR UPDATE')) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 37

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 ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 50

def locked
  @ast.lock
end

#on(*exprs) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 54

def on *exprs
  @ctx.froms.constraint = Nodes::On.new(collapse(exprs))
  self
end

#order(*expr) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 116

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 ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 172

def order_clauses
  Visitors::OrderClauses.new(@engine).accept(@ast).map { |x|
    Nodes::SqlLiteral.new x
  }
end

#orders ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 124

def orders
  @ast.orders
end

#project(*projections) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 107

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

#skip(amount) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 20

def skip amount
  @ast.offset = Nodes::Offset.new(amount)
  self
end

#take(limit) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 159

def take limit
  @ast.limit = Nodes::Limit.new(limit)
  @ctx.top   = Nodes::Top.new(limit)
  self
end

#taken ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 12

def taken
  @ast.limit && @ast.limit.expr
end

#to_a ⇒ Object

:nodoc:



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# File 'lib/arel/select_manager.rb', line 198

def to_a # :nodoc:
  warn "to_a is deprecated. Please remove it from #{caller[0]}"
  # FIXME: I think `select` should be made public...
  @engine.connection.send(:select, to_sql, 'AREL').map { |x| Row.new(x) }
end

#union(operation, other = nil) ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 139

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 ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 31

def where_clauses
  #warn "where_clauses is deprecated" if $VERBOSE
  to_sql = Visitors::ToSql.new @engine
  @ctx.wheres.map { |c| to_sql.accept c }
end

#where_sql ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 132

def where_sql
  return if @ctx.wheres.empty?

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

#wheres ⇒ Object 



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# File 'lib/arel/select_manager.rb', line 128

def wheres
  Compatibility::Wheres.new @engine, @ctx.wheres
end