From 16e7273245473bb6466a79a38702a52387bab44d Mon Sep 17 00:00:00 2001 From: Aaron Patterson Date: Thu, 12 Aug 2010 16:19:54 -0700 Subject: full sql statement generation --- lib/arel.rb | 1 + lib/arel/nodes.rb | 1 + lib/arel/nodes/select.rb | 13 +++++++++++++ lib/arel/tree_manager.rb | 31 +++++++++++++++++++++++++++++++ lib/arel/visitors/to_sql.rb | 12 ++++++++++++ spec/arel/tree_manager.rb | 44 ++++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 102 insertions(+) create mode 100644 lib/arel/nodes/select.rb create mode 100644 lib/arel/tree_manager.rb create mode 100644 spec/arel/tree_manager.rb diff --git a/lib/arel.rb b/lib/arel.rb index ea9a462d1f..e1d34d4561 100644 --- a/lib/arel.rb +++ b/lib/arel.rb @@ -1,6 +1,7 @@ require 'arel/version' require 'arel/table' require 'arel/attributes' +require 'arel/tree_manager' require 'arel/nodes' require 'arel/visitors/to_sql' diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb index 07a687405f..53c17a8cca 100644 --- a/lib/arel/nodes.rb +++ b/lib/arel/nodes.rb @@ -1,2 +1,3 @@ require 'arel/nodes/equality' require 'arel/nodes/sql_literal' +require 'arel/nodes/select' diff --git a/lib/arel/nodes/select.rb b/lib/arel/nodes/select.rb new file mode 100644 index 0000000000..8f68adbcd5 --- /dev/null +++ b/lib/arel/nodes/select.rb @@ -0,0 +1,13 @@ +module Arel + module Nodes + class Select + attr_reader :froms, :projections, :wheres + + def initialize + @froms = [] + @projections = [] + @wheres = [] + end + end + end +end diff --git a/lib/arel/tree_manager.rb b/lib/arel/tree_manager.rb new file mode 100644 index 0000000000..b111ca9557 --- /dev/null +++ b/lib/arel/tree_manager.rb @@ -0,0 +1,31 @@ +module Arel + class TreeManager + def initialize engine + @engine = engine + @statement_list = [] + + # default to Select + @statement_list << Nodes::Select.new + end + + def from table + @statement_list.last.froms << table + self + end + + def project projection + @statement_list.last.projections << projection + self + end + + def where expr + @statement_list.last.wheres << expr + self + end + + def to_sql + viz = Visitors::ToSql.new @engine + viz.accept @statement_list.last + end + end +end diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb index ba92ca7ef1..bb2a4d07e8 100644 --- a/lib/arel/visitors/to_sql.rb +++ b/lib/arel/visitors/to_sql.rb @@ -12,6 +12,18 @@ module Arel end private + def visit_Arel_Nodes_Select o + [ + "SELECT #{o.projections.map { |x| visit x }.join ', '}", + "FROM #{o.froms.map { |x| visit x }.join ', ' }", + ("WHERE #{o.wheres.map { |x| visit x }.join ' AND ' }" unless o.wheres.blank?) + ].compact.join ' ' + end + + def visit_Arel_Table o + quote_table_name o.name + end + def visit_Arel_Nodes_Equality o "#{visit o.left} = #{visit o.right}" end diff --git a/spec/arel/tree_manager.rb b/spec/arel/tree_manager.rb new file mode 100644 index 0000000000..513b41e305 --- /dev/null +++ b/spec/arel/tree_manager.rb @@ -0,0 +1,44 @@ +require 'spec_helper' + +module Arel + describe 'tree manager' do + describe 'where' do + it "knows where" do + table = Table.new :users + manager = Arel::TreeManager.new Table.engine + manager.from(table).project(table['id']) + manager.where(table['id'].eq(1)) + manager.to_sql.should == %{ + SELECT "users"."id" + FROM "users" + WHERE "users"."id" = 1 + }.gsub("\n", '').gsub(/(^\s*|\s*$)/, '').squeeze(' ') + end + + it "chains" do + table = Table.new :users + manager = Arel::TreeManager.new Table.engine + manager.from(table) + manager.project(table['id']).where(table['id'].eq 1).should == manager + end + end + + describe 'from' do + it "makes sql" do + table = Table.new :users + manager = Arel::TreeManager.new Table.engine + + manager.from table + manager.project table['id'] + manager.to_sql.should == 'SELECT "users"."id" FROM "users"' + end + + it "chains" do + table = Table.new :users + manager = Arel::TreeManager.new Table.engine + manager.from(table).project(table['id']).should == manager + manager.to_sql.should == 'SELECT "users"."id" FROM "users"' + end + end + end +end -- cgit v1.2.3