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"self" and or

Browse source 
=============

This lines mean the same:

	User.smql :self => {:id => 1}
	User.smql :id => 1
	User.smql 'self.id' => 1
	User.smql 'self.self.self.self.id' => 1

self is like a reflection to itself.

Very userful if you need the new disjunction:

	User.smql :self => [{:surname => 'Mueller', :givenname => 'Michael'}, {:givenname => 'Horst', :surname => 'Schlemmer'}], :firm => {:name => 'Hotel an der Elbe'}

SmqlToAR::Column
----------------

Rejects every `self`,  so it is really like no self,
but you use `'self'` as like as a simple reflection.
You can ask,  if it is self via Column#self?

SmqlToAR::QueryBuilder
======================

joins:  The old `#join`. Renames because SmqlToAR::And and SmqlToAR::Or which has Array#join,
        so we cannot delegate `#join` to the QueryBuilder.

`#where`
--------

Now only one argument!  Needed for SmqlToAR::And and SmqlToAR::Or.

`#build` will generates LEFT OUTER JOINS now.  Needed for disjunctions.
The most queries will work like before.
Problems:

	User.smql :articles => {}

Before it will return all users with articles,  now it will return also users without articles.
If you want to have only all users with articles,  you ask:

	User.smql :articles => {:id => true}

Will fail if id IS NULL,  but this should not happen. ;)

`SmqlToAR::And` and `SmqlToAR::Or`
==================================

`SmqlToAR::QueryBuilder`-proxies.  QueryBuilder let them build where-clauses.
And will will produce a conjunction and  Or a disjunction of course.
They delegates all QueryBuilder-methods to QueryBuilder.
Only `#where` will stored local and `#build` will do it partial.

They have the same superclass: `SmqlToAR::SubBuilder`.

The small changes
=================

* `SmqlToAR.reload_library`:  Reloads SmqlToAR-lib.  Useful while development.
* `SmqlToAR::ConditionTypes#conditions`:  Return all Conditions.  `#try_parse` uses it.
* Some classes have a new `#inspect`.
* `SmqlToAR::ConditionTypes#Exists` / `NotExists`:
  `{:id => true}` / `{:id => false}`:
  This object has setted an id or not?  `#id` must exists as column of course!
	Uses `IS NOT NULL` and `IS NULL`.
This commit is contained in:
Denis Knauf 2011-10-05 13:25:56 +02:00
parent 93fd3eeda4
commit 2fdc45d1d5
3 changed files with 184 additions and 73 deletions
Download patch file Download diff file Expand all files Collapse all files

128
lib/smql_to_ar/query_builder.rb
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@ -29,30 +29,34 @@ class SmqlToAR
end
attr_reader :table_alias, :model, :table_model, :base_table, :_where, :_select, :_wobs, :_joins, :prefix, :_vid
attr_accessor :logger
attr_accessor :logger, :limit, :offset
def initialize model, prefix = nil, base_table
def initialize model, prefix = nil
@prefix = "smql"
@logger = SmqlToAR.logger
@table_alias = Hash.new do |h, k|
k = Array.wrap k
h[k] = "#{@prefix},#{k.join(',')}"
j = Array.wrap( k).compact
h[k] = h.key?(j) ? h[j] : "#{@prefix},#{j.join(',')}"
end
@_vid, @_where, @_wobs, @model, @quoter = 0, [], {}, model, model.connection
@base_table = base_table.blank? ? [model.table_name.to_sym] : Array.wrap( base_table)
@_vid, @_where, @_wobs, @model, @quoter = 0, SmqlToAR::And[], {}, model, model.connection
@base_table = [model.table_name.to_sym]
@table_alias[ @base_table] = @base_table.first
t = quote_table_name @table_alias[ @base_table]
@_select, @_joins, @_joined, @_includes, @_order = ["DISTINCT #{t}.*"], "", [], [], []
@_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')
# 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
def where cond
@_where.push cond
self
end
@ -75,12 +79,12 @@ class SmqlToAR
end
def build_join orig, pretable, table, prekey, key
" JOIN #{orig} AS #{quote_table_name table} ON #{column pretable, prekey} = #{column table, key} "
" LEFT OUTER JOIN #{orig} AS #{quote_table_name table} ON #{column pretable, prekey} = #{column table, key} "
end
def sub_join table, col, model, query
prefix, base_table = "#{@prefix}_sub", col.col
join_ table, model, "(#{query.build( prefix, base_table).ar.to_sql})"
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
@ -116,7 +120,8 @@ class SmqlToAR
self
end
def join table, model
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
@ -136,40 +141,22 @@ class SmqlToAR
@_order.push "#{column table, col} #{:DESC == o ? :DESC : :ASC}"
end
def limit count
@_limit = count
end
def offset count
@_offset = count
end
class Dummy
def method_missing m, *a, &e
#p :dummy => m, :pars => a, :block => e
self
end
end
def build_ar
where_str = @_where.collect do |w|
w = Array.wrap w
1 == w.length ? w.first : "( #{w.join( ' OR ')} )"
end.join ' AND '
where_str = @_where.type_correction!.optimize!.tap {|x| p x }.build_where
incls = {}
@_includes.each do |inc|
b = incls
inc[1..-1].collect {|rel| b = b[rel] ||= {} }
end
@logger.debug incls: incls, joins: @_joins
@logger.info where: where_str, wobs: @_wobs
@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 = @model.limit @limit if @limit
@model = @model.offset @offset if @offset
@model
end
@ -189,4 +176,73 @@ class SmqlToAR
@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
p init: self, parent: parent
@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!
p optimize: self
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!
p optimized: self
p ext: ext
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
end
class And < SubBuilder
def default; SmqlToAR::Or; end
def build_where
join ' AND '
end
end
class Or < SubBuilder
def build_where
join ' OR '
end
end
end