Class: QueryBuilder::Query

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(processor_class) ⇒ Query

Returns a new instance of Query.



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# File 'lib/query_builder/query.rb', line 15

def initialize(processor_class)
  @processor_class = processor_class
  @tables = []
  @table_alias = {}
  @join_tables = {}
  @needed_join_tables = {}
  @attributes_alias   = {}
  @key_value_tables   = {}
  @where = []
end

Instance Attribute Details

#attributes_alias ⇒ Object

Returns the value of attribute attributes_alias.



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# File 'lib/query_builder/query.rb', line 5

def attributes_alias
  @attributes_alias
end

#context ⇒ Object

Returns the value of attribute context.



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# File 'lib/query_builder/query.rb', line 5

def context
  @context
end

#distinct ⇒ Object

Returns the value of attribute distinct.



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# File 'lib/query_builder/query.rb', line 5

def distinct
  @distinct
end

#error ⇒ Object

Returns the value of attribute error.



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# File 'lib/query_builder/query.rb', line 5

def error
  @error
end

#group ⇒ Object

Returns the value of attribute group.



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# File 'lib/query_builder/query.rb', line 5

def group
  @group
end

#having ⇒ Object

Returns the value of attribute having.



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# File 'lib/query_builder/query.rb', line 5

def having
  @having
end

#key_value_tables ⇒ Object

Returns the value of attribute key_value_tables.



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# File 'lib/query_builder/query.rb', line 5

def key_value_tables
  @key_value_tables
end

#limit ⇒ Object

Returns the value of attribute limit.



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# File 'lib/query_builder/query.rb', line 5

def limit
  @limit
end

#main_class ⇒ Object

Return the class of resulting objects (different from default_class if the value has been changed by the query building process).



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# File 'lib/query_builder/query.rb', line 33

def main_class
  @main_class
end

#offset ⇒ Object

Returns the value of attribute offset.



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# File 'lib/query_builder/query.rb', line 5

def offset
  @offset
end

#order ⇒ Object

Returns the value of attribute order.



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# File 'lib/query_builder/query.rb', line 5

def order
  @order
end

#page_size ⇒ Object

Returns the value of attribute page_size.



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# File 'lib/query_builder/query.rb', line 5

def page_size
  @page_size
end

#pagination_key ⇒ Object

Returns the value of attribute pagination_key.



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# File 'lib/query_builder/query.rb', line 5

def pagination_key
  @pagination_key
end

#processor_class ⇒ Object

Returns the value of attribute processor_class.



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# File 'lib/query_builder/query.rb', line 5

def processor_class
  @processor_class
end

#select ⇒ Object

Returns the value of attribute select.



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# File 'lib/query_builder/query.rb', line 5

def select
  @select
end

#table_alias ⇒ Object

Returns the value of attribute table_alias.



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# File 'lib/query_builder/query.rb', line 5

def table_alias
  @table_alias
end

#tables ⇒ Object

Returns the value of attribute tables.



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# File 'lib/query_builder/query.rb', line 5

def tables
  @tables
end

#where ⇒ Object

Returns the value of attribute where.



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# File 'lib/query_builder/query.rb', line 5

def where
  @where
end

Class Method Details

.adapter ⇒ Object 



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# File 'lib/query_builder/query.rb', line 10

def adapter
  @adapter ||= ActiveRecord::Base.connection.class.name.split('::').last[/(.+)Adapter/,1].downcase
end

Instance Method Details

#add_filter(filter) ⇒ Object 



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# File 'lib/query_builder/query.rb', line 55

def add_filter(filter)
  @where << filter
end

#add_key_value_table(use_name, index_table, key, &block) ⇒ Object

Add a table to ‘import’ a key/value based field. This method ensures that a given field is only included once for each context.



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

def add_key_value_table(use_name, index_table, key, &block)
  key_tables = (@key_value_tables[table] ||= {})
  key_table = (key_tables[use_name] ||= {})
  if alias_table = key_table[key]
    # done, the index_table has been used for the given key in the current context
  else
    # insert the new table
    add_table(use_name, index_table, false)
    alias_table = key_table[key] = table(use_name)
    # Let caller configure the filter (join).
    block.call(alias_table)
  end
  alias_table
end

#add_select(field, fname) ⇒ Object 



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# File 'lib/query_builder/query.rb', line 133

def add_select(field, fname)
  @select ||= ["#{main_table}.*"]
  @select << "#{field} AS #{quote_column_name(fname)}"
  @attributes_alias[fname] = field
end

#add_table(use_name, table_name = nil, avoid_alias = true) ⇒ Object

‘avoid_alias’ is used when parsing the last element so that it takes the real table name (nodes, not no1). We need this because we can use ‘OR’ between parts and we thus need the same table reference.



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# File 'lib/query_builder/query.rb', line 111

def add_table(use_name, table_name = nil, avoid_alias = true)
  alias_name = get_alias(use_name, table_name, avoid_alias)
  add_alias_to_tables(table_name || use_name, alias_name)
end

#default_class ⇒ Object

Return the default class of resulting objects (usually the base class).



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# File 'lib/query_builder/query.rb', line 48

def default_class
  @default_class ||= begin
    klass = @processor_class.main_class
    QueryBuilder.resolve_const(klass)
  end
end

#dup ⇒ Object

Duplicate query, avoiding sharing some arrays and hash



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# File 'lib/query_builder/query.rb', line 165

def dup
  other = super
  %w{tables table_alias where tables key_value_tables}.each do |k|
    other.send("#{k}=", other.send(k).dup)
  end
  other
end

#filter ⇒ Object 



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# File 'lib/query_builder/query.rb', line 206

def filter
  @where.reverse.join(' AND ')
end

#main_table ⇒ Object 



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# File 'lib/query_builder/query.rb', line 26

def main_table
  # @main_table is only used in custom queries
  @main_table || processor_class.main_table
end

#master_class(after_class = ActiveRecord::Base) ⇒ Object 



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# File 'lib/query_builder/query.rb', line 37

def master_class(after_class = ActiveRecord::Base)
  klass = main_class
  klass = klass.first if klass.kind_of?(Array)
  begin
    up = klass.superclass
    return klass if up == after_class
  end while klass = up
  return main_class
end

#needs_join_table(table_name1, type, table_name2, clause, join_name = nil) ⇒ Object

Use this method to add a join to another table (added only once for each join name). nodes JOIN idx_nodes_string AS id1 ON … FIXME: can we remove this ? It seems buggy (JOIN in or clauses)



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# File 'lib/query_builder/query.rb', line 146

def needs_join_table(table_name1, type, table_name2, clause, join_name = nil)
  join_name ||= "#{table_name1}=#{type}=#{table_name2}"
  @needed_join_tables[join_name] ||= {}
  @needed_join_tables[join_name][table] ||= begin
    # define join for this part ('table' = unique for each part)

    # don't add to list of tables, just get unique alias name
    second_table = get_alias(table_name2)

    # create join
    first_table = table(table_name1)

    @join_tables[first_table] ||= []
    @join_tables[first_table] << "#{type} JOIN #{second_table} ON #{clause.gsub('TABLE1',first_table).gsub('TABLE2',second_table)}"
    second_table
  end
end

#quote_column_name(name) ⇒ Object 



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# File 'lib/query_builder/query.rb', line 210

def quote_column_name(name)
  connection.quote_column_name(name)
end

#rebuild_attributes_hash! ⇒ Object 



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# File 'lib/query_builder/query.rb', line 187

def rebuild_attributes_hash!
  @attributes_alias = {}
  (@select || []).each do |field|
    if field =~ %r{\A(.*)\s+AS\s+(.+)\Z}i
      key, value = $2, $1
      if key =~ /('|"|`)(.*)\1/
        # TODO: is this clean enough unquoting ?
        key = $2
      end
      @attributes_alias[key] = value
    elsif field =~ %r{^(\w+\.|)([^\*]+)$}
      @attributes_alias[$2] = field
    end
  end
  # Force rebuild
  @select_keys = nil
end

#rebuild_tables! ⇒ Object

Used after setting @tables from custom query.



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# File 'lib/query_builder/query.rb', line 174

def rebuild_tables!
  @table_alias = {}
  @tables.each do |t|
    if t =~ /\A(.+)\s+AS\s+(.+)\Z/
      base, use_name = $1, $2
    else
      base = use_name = t
    end
    @table_alias[base] ||= []
    @table_alias[base] << use_name
  end
end

#select_keys ⇒ Object

Return all explicit selected keys (currently selection is only available in custom queries) For example, sql such as “SELECT form.*, MAX(form.date) AS last_date” would provice ‘last_date’ key.



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# File 'lib/query_builder/query.rb', line 61

def select_keys
  @select_keys ||= @attributes_alias.keys.compact
end

#sql(bindings, type = :find) ⇒ Object

Convert the query object into an SQL query.

Parameters

bindings<Binding>

Binding context in which to evaluate bind clauses (query arguments).

type<Symbol>

Type of SQL query (:find or :count)

Returns

NilClass

If the query is not valid and “ignore_warnings” was not set to true during initialize.

String

An SQL query, ready for execution (no more bind variables).

Examples

query.sql(binding)

> “SELECT objects.* FROM objects WHERE objects.project_id = 12489”

query.sql(bindings, :count)

> “SELECT COUNT(*) FROM objects WHERE objects.project_id = 12489”



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# File 'lib/query_builder/query.rb', line 104

def sql(bindings, type = :find)
  statement, bind_values = build_statement(type)
  statement.gsub('?') { eval_bound_value(bind_values.shift, connection, bindings) }
end

#table(table_name = main_table, index = 0) ⇒ Object 



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# File 'lib/query_builder/query.rb', line 139

def table(table_name = main_table, index = 0)
  @table_alias[table_name] ? @table_alias[table_name][index - 1] : nil
end

#to_s(type = :find) ⇒ Object

Convert query object to a string. This string should then be evaluated.

Parameters

type<Symbol>

Type of query to build (:find or :count).

Returns

NilClass

If the query is not valid and “ignore_warnings” was not set to true during initialize.

String

A string representing the query with its bind parameters.

Examples

query.to_s

> “[%Qobjects.* FROM objects WHERE objects.project_id = ?, project_id]”

DummyQuery.new(“nodes in site”).to_s

> “%Qobjects.* FROM objects”

query.to_s(:count)

> “[%QCOUNT(*) FROM objects WHERE objects.project_id = ?, project_id]”



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# File 'lib/query_builder/query.rb', line 83

def to_s(type = :find)
  statement, bind_values = build_statement(type)
  bind_values.empty? ? "%Q{#{statement}}" : "[#{[["%Q{#{statement}}"] + bind_values].join(', ')}]"
end