Class: SmqlToAR::QueryBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/smql_to_ar/query_builder.rb

Overview

Baut die Queries zusammen.

Defined Under Namespace

Classes: Aliases, Vid

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(model, prefix = nil) ⇒ QueryBuilder

Returns a new instance of QueryBuilder.



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# File 'lib/smql_to_ar/query_builder.rb', line 70

def initialize model, prefix = nil
	@prefix = "smql"
	@logger = SmqlToAR.logger
	@table_alias = Aliases.new @prefix
	@_vid, @_where, @_wobs, @model, @quote = 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

Instance Attribute Details

#_joins ⇒ Object (readonly)

Returns the value of attribute _joins.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def _joins
  @_joins
end

#_select ⇒ Object (readonly)

Returns the value of attribute _select.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def _select
  @_select
end

#_vid ⇒ Object (readonly)

Returns the value of attribute _vid.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def _vid
  @_vid
end

#_where ⇒ Object (readonly)

Returns the value of attribute _where.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def _where
  @_where
end

#_wobs ⇒ Object (readonly)

Returns the value of attribute _wobs.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def _wobs
  @_wobs
end

#base_table ⇒ Object (readonly)

Returns the value of attribute base_table.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def base_table
  @base_table
end

#limit ⇒ Object

Returns the value of attribute limit.



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# File 'lib/smql_to_ar/query_builder.rb', line 68

def limit
  @limit
end

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/smql_to_ar/query_builder.rb', line 68

def logger
  @logger
end

#model ⇒ Object (readonly)

Returns the value of attribute model.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def model
  @model
end

#offset ⇒ Object

Returns the value of attribute offset.



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# File 'lib/smql_to_ar/query_builder.rb', line 68

def offset
  @offset
end

#prefix ⇒ Object (readonly)

Returns the value of attribute prefix.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def prefix
  @prefix
end

#table_alias ⇒ Object (readonly)

Returns the value of attribute table_alias.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def table_alias
  @table_alias
end

#table_model ⇒ Object (readonly)

Returns the value of attribute table_model.



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# File 'lib/smql_to_ar/query_builder.rb', line 67

def table_model
  @table_model
end

Class Method Details

.calculate(operation, column_name, options = nil) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 204

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

Instance Method Details

#build_ar ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 185

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

#build_join(orig, pretable, table, prekey, key) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 118

def build_join orig, pretable, table, prekey, key
	"\tLEFT JOIN #{orig} AS #{quote_table_name table}\n\tON #{column pretable, prekey} = #{column table, key}\n"
end

#column(table, name) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 114

def column table, name
	"#{quote_table_name table}.#{quote_column_name name}"
end

#fix_calculate ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 203

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

#includes(table) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 168

def includes table
	@_includes.push table
	self
end

#inspect ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 84

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

#join_(table, model, query, pretable = nil) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 127

def join_ table, model, query, pretable = nil
	pretable ||= table[0...-1]
	@table_model[ table] = model
	@table_model.rehash
	premodel = @table_model.find {|k,v| pretable == k }[1]
	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
		through_table = table[0...-1]+[Column::Col.new( through.name, table.last.as)]
		srctable = through_table+[Column::Col.new( refl.source_reflection.name, table.last.as)]
		@table_model[ srctable] = model
		@table_alias[ table] = @table_alias[ srctable]
		join_ through_table, through.klass, quote_table_name( through.table_name)
		join_ srctable, refl.klass, query, through_table
	when ActiveRecord::Reflection::AssociationReflection
		case refl.macro
		when :has_many, :has_one
			@_joins += build_join query, pretable, t, premodel.primary_key, refl.foreign_key
		when :belongs_to
			@_joins += build_join query, pretable, t, refl.foreign_key, 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.foreign_key
			@_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} #{refl.macro.inspect}"
	end
	self
end

#joins(table, model) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 161

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

#order(table, col, o) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 178

def order table, col, o
	ct = column table, col
	@_select.push ct
	@_order.push "#{ct} #{:DESC == o ? :DESC : :ASC}"
	self
end

#quote_column_name(name) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 102

def quote_column_name name
	@quote.quote_column_name( name).gsub /"\."/, ','
end

#quote_table_name(name) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 106

def quote_table_name name
	name = case name
		when Array, Column::Col then @table_alias[Array.wrap name]
		else name.to_s
		end
	@quote.quote_table_name name
end

#select(col) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 173

def select col
	@_select.push quote_column_name( @table_alias[col])
	self
end

#sub_joins(table, col, model, query) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 122

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

#to_ar ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 213

def to_ar
	build_ar
	fix_calculate
	@model
end

#vid ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 82

def vid()  Vid.new( @_vid+=1)  end

#where(cond) ⇒ Object

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 )



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# File 'lib/smql_to_ar/query_builder.rb', line 92

def where cond
	@_where.push cond
	self
end

#wobs(vals) ⇒ Object 



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# File 'lib/smql_to_ar/query_builder.rb', line 97

def wobs vals
	@_wobs.update vals
	self
end