module Sequel::Postgres::AutoParameterizeInArray

Enable automatically parameterizing queries.

Public Instance Methods

complex_expression_sql_append(sql, op, args) click to toggle source

Transform column IN (…) expressions into column = ANY($) and column NOT IN (…) expressions into column != ALL($) using an array bound variable for the ANY/ALL argument, if all values inside the predicate are of the same type and the type is handled by the extension. This is the same optimization PostgreSQL performs internally, but this reduces the number of bound variables.

Calls superclass method
   # File lib/sequel/extensions/pg_auto_parameterize_in_array.rb
47 def complex_expression_sql_append(sql, op, args)
48   case op
49   when :IN, :"NOT IN"
50     l, r = args
51     if auto_param?(sql) && (type = _bound_variable_type_for_array(r))
52       if op == :IN 
53         op = :"="
54         func = :ANY
55       else
56         op = :!=
57         func = :ALL
58       end
59       args = [l, Sequel.function(func, Sequel.pg_array(r, type))]
60     end
61   end
62 
63   super
64 end

Private Instance Methods

_bound_variable_type_for_array(r) click to toggle source

The bound variable type string to use for the bound variable array. Returns nil if a bound variable should not be used for the array.

    # File lib/sequel/extensions/pg_auto_parameterize_in_array.rb
 70 def _bound_variable_type_for_array(r)
 71   return unless Array === r && r.size > 1
 72   classes = r.map(&:class)
 73   classes.uniq!
 74   classes.delete(NilClass)
 75   return unless classes.size == 1
 76 
 77   klass = classes[0]
 78   if klass == Integer
 79     # This branch is not taken on Ruby <2.4, because of the Fixnum/Bignum split.
 80     # However, that causes no problems as pg_auto_parameterize handles integer
 81     # arrays natively (though the SQL used is different)
 82     "int8"
 83   elsif klass == String
 84     "text" if db.typecast_value(:boolean, db.opts[:treat_string_list_as_text_array])
 85   elsif klass == BigDecimal
 86     "numeric"
 87   elsif klass == Date
 88     "date"
 89   elsif klass == Time
 90     @db.cast_type_literal(Time)
 91   elsif klass == Float
 92     # PostgreSQL treats literal floats as numeric, not double precision
 93     # But older versions of PostgreSQL don't handle Infinity/NaN in numeric
 94     r.all?{|v| v.nil? || v.finite?} ? "numeric" : "double precision"
 95   elsif klass == Sequel::SQLTime
 96     "time"
 97   elsif klass == DateTime
 98     @db.cast_type_literal(DateTime)
 99   elsif klass == Sequel::SQL::Blob
100     "bytea"
101   end
102 end