Class: Sequel::MySQL::Dataset

#fetch_rows(sql) ⇒ Object

Yield all rows matching this dataset.
#graph ⇒ Object

Don’t allow graphing a dataset that splits multiple statements.
#split_multiple_result_sets ⇒ Object

Makes each yield arrays of rows, with each array containing the rows for a given result set.

Methods included from SQL::NumericMethods

Methods included from SQL::ComplexExpressionMethods

#extract, #sql_boolean, #sql_number, #sql_string

Methods included from SQL::CastMethods

#cast, #cast_numeric, #cast_string

Methods included from SQL::BooleanMethods

Methods included from SQL::AliasMethods

#as

Constructor Details

This class inherits a constructor from Sequel::Dataset

Instance Method Details

#fetch_rows(sql) ⇒ `Object`

Yield all rows matching this dataset. If the dataset is set to split multiple statements, yield arrays of hashes one per statement instead of yielding results for all statements as hashes.

# File 'lib/sequel/adapters/mysql.rb', line 295

def fetch_rows(sql)
  execute(sql) do |r|
    i = -1
    cps = db.conversion_procs
    cols = r.fetch_fields.map do |f| 
      # Pretend tinyint is another integer type if its length is not 1, to
      # avoid casting to boolean if Sequel::MySQL.convert_tinyint_to_bool
      # is set.
      type_proc = f.type == 1 && cast_tinyint_integer?(f) ? cps[2] : cps[f.type]
      [output_identifier(f.name), type_proc, i+=1]
    end
    @columns = cols.map(&:first)
    if opts[:split_multiple_result_sets]
      s = []
      yield_rows(r, cols){|h| s << h}
      yield s
    else
      yield_rows(r, cols){|h| yield h}
    end
  end
  self
end

#graph ⇒ `Object`

Don’t allow graphing a dataset that splits multiple statements

Raises:

(Error)

# File 'lib/sequel/adapters/mysql.rb', line 319

def graph(*)
  raise(Error, "Can't graph a dataset that splits multiple result sets") if opts[:split_multiple_result_sets]
  super
end

#split_multiple_result_sets ⇒ `Object`

Makes each yield arrays of rows, with each array containing the rows for a given result set. Does not work with graphing. So you can submit SQL with multiple statements and easily determine which statement returned which results.

Modifies the row_proc of the returned dataset so that it still works as expected (running on the hashes instead of on the arrays of hashes). If you modify the row_proc afterward, note that it will receive an array of hashes instead of a hash.

Raises:

(Error)

# File 'lib/sequel/adapters/mysql.rb', line 333

def split_multiple_result_sets
  raise(Error, "Can't split multiple statements on a graphed dataset") if opts[:graph]
  ds = clone(:split_multiple_result_sets=>true)
  ds.row_proc = proc{|x| x.map{|h| row_proc.call(h)}} if row_proc
  ds
end

Class: Sequel::MySQL::Dataset

Overview

Constant Summary

Constants included from PreparedStatements::DatasetMethods

Constants included from DatasetMethods

Constants included from Dataset::Replace

Constants inherited from Dataset

Instance Attribute Summary

Attributes inherited from Dataset

Instance Method Summary collapse

Methods included from PreparedStatements::DatasetMethods

Methods included from Dataset::StoredProcedures

Methods included from DatasetMethods

Methods included from Dataset::Replace

Methods inherited from Dataset

Methods included from Sequel::Metaprogramming

Methods included from SQL::StringMethods

Methods included from SQL::OrderMethods