Class: Sequel::Oracle::Dataset

Inherits:
Dataset show all
Defined in:
lib/sequel_core/adapters/oracle.rb

Constant Summary

Constants inherited from Dataset

Dataset::AND_SEPARATOR, Dataset::BOOL_FALSE, Dataset::BOOL_TRUE, Dataset::COLUMN_CHANGE_OPTS, Dataset::COLUMN_REF_RE1, Dataset::COLUMN_REF_RE2, Dataset::COLUMN_REF_RE3, Dataset::COMMA_SEPARATOR, Dataset::COUNT_FROM_SELF_OPTS, Dataset::COUNT_OF_ALL_AS_COUNT, Dataset::DATASET_CLASSES, Dataset::DATE_FORMAT, Dataset::MUTATION_METHODS, Dataset::NOTIMPL_MSG, Dataset::NULL, Dataset::N_ARITY_OPERATORS, Dataset::PREPARED_ARG_PLACEHOLDER, Dataset::QUESTION_MARK, Dataset::STOCK_COUNT_OPTS, Dataset::STOCK_TRANSFORMS, Dataset::TIMESTAMP_FORMAT, Dataset::TWO_ARITY_OPERATORS, Dataset::WILDCARD

Instance Attribute Summary

Attributes inherited from Dataset

#db, #opts, #quote_identifiers, #row_proc

Instance Method Summary collapse

Methods inherited from Dataset

#<<, #[], #[]=, #aliased_expression_sql, #all, #and, #as, #avg, #call, #case_expression_sql, #clone, #column_all_sql, #columns, #columns!, #complex_expression_sql, #count, #create_or_replace_view, #create_view, dataset_classes, #def_mutation_method, def_mutation_method, #delete, #delete_sql, #each, #each_page, #except, #exclude, #exists, #filter, #first, #first_source, #from, #from_self, #function_sql, #get, #graph, #grep, #group, #group_and_count, #having, inherited, #initialize, #insert, #insert_multiple, #insert_sql, #inspect, #intersect, #interval, #invert, #irregular_function_sql, #join_clause_sql, #join_on_clause_sql, #join_table, #join_using_clause_sql, #last, #limit, #map, #max, #min, #model_classes, #multi_insert, #multi_insert_sql, #naked, #or, #order, #order_more, #ordered_expression_sql, #paginate, #polymorphic_key, #prepare, #print, #qualified_identifier_sql, #query, #quote_identifier, #quote_identifiers?, #quoted_identifier, #range, #reverse_order, #select, #select_all, #select_more, #server, #set, #set_defaults, #set_graph_aliases, #set_model, #set_overrides, #single_record, #single_value, #subscript_sql, #sum, #symbol_to_column_ref, #table_exists?, #to_csv, #to_hash, #transform, #transform_load, #transform_save, #unfiltered, #union, #uniq, #unordered, #update, #update_sql

Methods included from Enumerable

#send_each

Constructor Details

This class inherits a constructor from Sequel::Dataset

Instance Method Details

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/sequel_core/adapters/oracle.rb', line 96

def empty?
  db[:dual].where(exists).get(1) == nil
end

#fetch_rows(sql, &block) ⇒ Object 



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# File 'lib/sequel_core/adapters/oracle.rb', line 80

def fetch_rows(sql, &block)
  execute(sql) do |cursor|
    begin
      @columns = cursor.get_col_names.map {|c| c.downcase.to_sym}
      while r = cursor.fetch
        row = {}
        r.each_with_index {|v, i| row[columns[i]] = v unless columns[i] == :raw_rnum_}
        yield row
      end
    ensure
      cursor.close
    end
  end
  self
end

#literal(v) ⇒ Object 



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# File 'lib/sequel_core/adapters/oracle.rb', line 71

def literal(v)
  case v
  when OraDate
    literal(Time.local(*v.to_a))
  else
    super
  end
end

#select_sql(opts = nil) ⇒ Object Also known as: sql

Formats a SELECT statement using the given options and the dataset options.



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# File 'lib/sequel_core/adapters/oracle.rb', line 102

def select_sql(opts = nil)
  opts = opts ? @opts.merge(opts) : @opts

  if sql = opts[:sql]
    return sql
  end

  columns = opts[:select]
  select_columns = columns ? column_list(columns) : WILDCARD
  sql = opts[:distinct] ? \
  "SELECT DISTINCT #{select_columns}" : \
  "SELECT #{select_columns}"
  
  if opts[:from]
    sql << " FROM #{source_list(opts[:from])}"
  end
  
  if join = opts[:join]
    join.each{|j| sql << literal(j)}
  end

  if where = opts[:where]
    sql << " WHERE #{literal(where)}"
  end

  if group = opts[:group]
    sql << " GROUP BY #{expression_list(group)}"
  end

  if having = opts[:having]
    sql << " HAVING #{literal(having)}"
  end

  if union = opts[:union]
    sql << (opts[:union_all] ? \
      " UNION ALL #{union.sql}" : " UNION #{union.sql}")
  elsif intersect = opts[:intersect]
    sql << (opts[:intersect_all] ? \
      " INTERSECT ALL #{intersect.sql}" : " INTERSECT #{intersect.sql}")
  elsif except = opts[:except]
    sql << (opts[:except_all] ? \
      " EXCEPT ALL #{except.sql}" : " EXCEPT #{except.sql}")
  end

  if order = opts[:order]
    sql << " ORDER BY #{expression_list(order)}"
  end

  if limit = opts[:limit]
    if (offset = opts[:offset]) && (offset > 0)
      sql = "SELECT * FROM (SELECT raw_sql_.*, ROWNUM raw_rnum_ FROM(#{sql}) raw_sql_ WHERE ROWNUM <= #{limit + offset}) WHERE raw_rnum_ > #{offset}"
    else
      sql = "SELECT * FROM (#{sql}) WHERE ROWNUM <= #{limit}"
    end
  end

  sql
end