264 lines
7.8 KiB
Ruby
264 lines
7.8 KiB
Ruby
# SmqlToAR - Builds AR-querys: Converts SMQL to ActiveRecord
|
|
# Copyright (C) 2011 Denis Knauf
|
|
#
|
|
# This program is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
class SmqlToAR
|
|
#######################################################################################
|
|
# Baut die Queries zusammen.
|
|
class QueryBuilder
|
|
# Erzeugt einen eindeutigen Identikator "cX", wobei X iteriert wird.
|
|
class Vid
|
|
attr_reader :vid
|
|
def initialize( vid) @vid = vid end
|
|
def to_s() ":smql_c#{@vid}" end
|
|
def to_sym() "smql_c#{@vid}".to_sym end
|
|
alias sym to_sym
|
|
def to_i() @vid end
|
|
def === other
|
|
to_s === other || to_sym === other || to_i === other || self == other || self === other
|
|
end
|
|
end
|
|
|
|
class Aliases < Hash
|
|
def self.new prefix, *a, &e
|
|
e ||= lambda do |h, k|
|
|
j = Array.wrap( k).compact
|
|
h[k] = h.key?(j) ? h[j] : "#{prefix},#{j.collect( &:to_alias).join( ',')}"
|
|
end
|
|
super *a, &e
|
|
end
|
|
end
|
|
|
|
attr_reader :table_alias, :model, :table_model, :base_table, :_where, :_select, :_wobs, :_joins, :prefix, :_vid
|
|
attr_accessor :logger, :limit, :offset
|
|
|
|
def initialize model, prefix = nil
|
|
@prefix = "smql"
|
|
@logger = SmqlToAR.logger
|
|
@table_alias = Aliases.new @prefix
|
|
@_vid, @_where, @_wobs, @model, @quoter = 0, SmqlToAR::And[], {}, model, model.connection
|
|
@base_table = [Column::Col.new( model.table_name)]
|
|
@table_alias[ @base_table] = @base_table.first
|
|
t = quote_table_name @base_table.first.col
|
|
@_select, @_joins, @_joined, @_includes, @_order = ["DISTINCT #{t}.*"], "", [@base_table], [], []
|
|
@table_model = {@base_table => @model}
|
|
end
|
|
|
|
def vid() Vid.new( @_vid+=1) end
|
|
|
|
def inspect
|
|
"#<#{self.class.name}:#{"0x%x"% (self.object_id<<1)}|#{@prefix}:#{@base_table}:#{@model} vid=#{@_vid} where=#{@_where} wobs=#{@_wobs} select=#{@_select} aliases=#{@table_alias}>"
|
|
end
|
|
|
|
# Jede via where uebergebene Condition wird geodert und alle zusammen werden geundet.
|
|
# "Konjunktive Normalform". Allerdings duerfen Conditions auch Komplexe Abfragen enthalten.
|
|
# Ex: builder.where( ['a = a', 'b = c']).where( ['c = d', 'e = e']).where( 'x = y').where( ['( m = n AND o = p )', 'f = g'])
|
|
# #=> WHERE ( a = a OR b = c ) AND ( c = d OR e = e ) AND x = y ( ( m = n AND o = p ) OR f = g )
|
|
def where cond
|
|
@_where.push cond
|
|
self
|
|
end
|
|
|
|
def wobs vals
|
|
@_wobs.update vals
|
|
self
|
|
end
|
|
|
|
def quote_column_name name
|
|
@quoter.quote_column_name( name).gsub /"\."/, ','
|
|
end
|
|
|
|
def quote_table_name name
|
|
name = case name
|
|
when Array, Column::Col then @table_alias[Array.wrap name]
|
|
else name.to_s
|
|
end
|
|
@quoter.quote_table_name( name).gsub /"\."/, ','
|
|
end
|
|
|
|
def column table, name
|
|
"#{quote_table_name table}.#{quote_column_name name}"
|
|
end
|
|
|
|
def build_join orig, pretable, table, prekey, key
|
|
" LEFT JOIN #{orig} AS #{quote_table_name table} ON #{column pretable, prekey} = #{column table, key} "
|
|
end
|
|
|
|
def sub_joins table, col, model, query
|
|
prefix, base_table = "#{@prefix}_sub", col.relation.table_name
|
|
join_ table, model, "(#{query.build( prefix).ar.to_sql})"
|
|
end
|
|
|
|
def join_ table, model, query, pretable = nil
|
|
pretable ||= table[0...-1]
|
|
@table_model[ table] = model
|
|
premodel = @table_model[ pretable]
|
|
t = @table_alias[ table]
|
|
pt = quote_table_name table[ 0...-1]
|
|
refl = premodel.reflections[table.last.to_sym]
|
|
case refl
|
|
when ActiveRecord::Reflection::ThroughReflection
|
|
through = refl.through_reflection
|
|
throughtable = table[0...-1]+[Column::Col.new( through.name, table.last.as)]
|
|
srctable = throughtable+[Column::Col.new( refl.source_reflection.name, table.last.as)]
|
|
@table_model[ srctable] = model
|
|
@table_alias[ table] = @table_alias[ srctable]
|
|
join_ throughtable, through.klass, quote_table_name( through.table_name)
|
|
join_ srctable, refl.klass, query, throughtable
|
|
when ActiveRecord::Reflection::AssociationReflection
|
|
case refl.macro
|
|
when :has_many, :has_one
|
|
@_joins += build_join query, pretable, t, premodel.primary_key, refl.primary_key_name
|
|
when :belongs_to
|
|
@_joins += build_join query, pretable, t, refl.primary_key_name, premodel.primary_key
|
|
when :has_and_belongs_to_many
|
|
jointable = [Column::Col.new('')] + table
|
|
@_joins += build_join refl.options[:join_table], pretable, @table_alias[jointable], premodel.primary_key, refl.primary_key_name
|
|
@_joins += build_join query, jointable, t, refl.association_foreign_key, refl.association_primary_key
|
|
else raise BuilderError, "Unkown reflection macro: #{refl.macro.inspect}"
|
|
end
|
|
else raise BuilderError, "Unkown reflection type: #{refl.class.name}"
|
|
end
|
|
self
|
|
end
|
|
|
|
def joins table, model
|
|
table = table.flatten.compact
|
|
return self if @_joined.include? table # Already joined
|
|
join_ table, model, quote_table_name( model.table_name)
|
|
@_joined.push table
|
|
end
|
|
|
|
def includes table
|
|
@_includes.push table
|
|
self
|
|
end
|
|
|
|
def select col
|
|
@_select.push quote_column_name( @table_alias[col])
|
|
self
|
|
end
|
|
|
|
def order table, col, o
|
|
ct = column table, col
|
|
@_select.push ct
|
|
@_order.push "#{ct} #{:DESC == o ? :DESC : :ASC}"
|
|
self
|
|
end
|
|
|
|
def build_ar
|
|
where_str = @_where.type_correction!.optimize!.build_where
|
|
incls = {}
|
|
@_includes.each do |inc|
|
|
b = incls
|
|
inc[1..-1].collect {|rel| b = b[rel] ||= {} }
|
|
end
|
|
@model = @model.
|
|
select( @_select.join( ', ')).
|
|
joins( @_joins).
|
|
where( where_str, @_wobs).
|
|
order( @_order.join( ', ')).
|
|
includes( incls)
|
|
@model = @model.limit @limit if @limit
|
|
@model = @model.offset @offset if @offset
|
|
@model
|
|
end
|
|
|
|
def fix_calculate
|
|
def @model.calculate operation, column_name, options = nil
|
|
options = options.try(:dup) || {}
|
|
options[:distinct] = true unless options.except(:distinct).present?
|
|
column_name = klass.primary_key unless column_name.present?
|
|
super operation, column_name, options
|
|
end
|
|
self
|
|
end
|
|
|
|
def to_ar
|
|
build_ar
|
|
fix_calculate
|
|
@model
|
|
end
|
|
end
|
|
|
|
class SubBuilder < Array
|
|
attr_reader :parent, :_where
|
|
delegate :wobs, :joins, :includes, :sub_joins, :vid, :quote_column_name, :quoter, :quote_table_name, :column, :to => :parent
|
|
|
|
def initialize parent, tmp = false
|
|
@parent = parent
|
|
@parent.where self unless @parend.nil? && tmp
|
|
end
|
|
|
|
def new parent, tmp = false
|
|
super parent, tmp
|
|
#return parent if self.class == parent.class
|
|
#super parent
|
|
end
|
|
|
|
alias where push
|
|
|
|
def type_correction!
|
|
collect! do |sub|
|
|
if sub.kind_of? Array
|
|
sub = default[ *sub] unless sub.respond_to?( :type_correction!)
|
|
sub.type_correction!
|
|
end
|
|
sub
|
|
end
|
|
self
|
|
end
|
|
|
|
def optimize!
|
|
ext = []
|
|
collect! do |sub|
|
|
sub = sub.optimize! if sub.kind_of? Array
|
|
if self.class == sub.class
|
|
ext.push *sub
|
|
nil
|
|
elsif sub.blank?
|
|
nil
|
|
else
|
|
sub
|
|
end
|
|
end.compact!
|
|
push *ext
|
|
self
|
|
end
|
|
|
|
def inspect
|
|
"#{self.class.name.sub( /.*::/, '')}[ #{collect(&:inspect).join ', '}]"
|
|
end
|
|
def default() SmqlToAR::And end
|
|
def default_new( parent) default.new self, parent, false end
|
|
def collect_build_where
|
|
collect {|x| "( #{x.respond_to?( :build_where) ? x.build_where : x.to_s } )" }
|
|
end
|
|
end
|
|
|
|
class And < SubBuilder
|
|
def default; SmqlToAR::Or; end
|
|
def build_where
|
|
collect_build_where.join ' AND '
|
|
end
|
|
end
|
|
|
|
class Or < SubBuilder
|
|
def build_where
|
|
collect_build_where.join ' OR '
|
|
end
|
|
end
|
|
end
|