Class: Sequel::SQL::BooleanExpression

from_value_pairs(pairs, op=:AND, negate=false)

Take pairs of values (e.g. a hash or array of two element arrays) and converts it to a BooleanExpression. The operator and args used depends on the case of the right (2nd) argument:

0..10 - left >= 0 AND left <= 10
[1,2] - left IN (1,2)
nil - left IS NULL
true - left IS TRUE
false - left IS FALSE
/as/ - left ~ ‘as‘
:blah - left = blah
‘blah’ - left = ‘blah‘

If multiple arguments are given, they are joined with the op given (AND by default, OR possible). If negate is set to true, all subexpressions are inverted before used. Therefore, the following expressions are equivalent:

  ~from_value_pairs(hash)
  from_value_pairs(hash, :OR, true)

[Source]

     # File lib/sequel/sql.rb, line 983
983:       def self.from_value_pairs(pairs, op=:AND, negate=false)
984:         pairs = pairs.map{|l,r| from_value_pair(l, r)}
985:         pairs.map!{|ce| invert(ce)} if negate
986:         pairs.length == 1 ? pairs.at(0) : new(op, *pairs)
987:       end

invert(ce)

Invert the expression, if possible. If the expression cannot be inverted, raise an error. An inverted expression should match everything that the uninverted expression did not match, and vice-versa, except for possible issues with SQL NULL (i.e. 1 == NULL is NULL and 1 != NULL is also NULL).

  BooleanExpression.invert(:a) # NOT "a"

[Source]

      # File lib/sequel/sql.rb, line 1018
1018:       def self.invert(ce)
1019:         case ce
1020:         when BooleanExpression
1021:           case op = ce.op
1022:           when :AND, :OR
1023:             BooleanExpression.new(OPERTATOR_INVERSIONS[op], *ce.args.collect{|a| BooleanExpression.invert(a)})
1024:           else
1025:             BooleanExpression.new(OPERTATOR_INVERSIONS[op], *ce.args.dup)
1026:           end
1027:         when StringExpression, NumericExpression
1028:           raise(Sequel::Error, "cannot invert #{ce.inspect}")
1029:         when Constant
1030:           CONSTANT_INVERSIONS[ce] || raise(Sequel::Error, "cannot invert #{ce.inspect}")
1031:         else
1032:           BooleanExpression.new(:NOT, ce)
1033:         end
1034:       end

&(ce)

Always use an AND operator for & on BooleanExpressions

[Source]

      # File lib/sequel/sql.rb, line 1037
1037:       def &(ce)
1038:         BooleanExpression.new(:AND, self, ce)
1039:       end

sql_boolean()

Return self instead of creating a new object to save on memory.

[Source]

      # File lib/sequel/sql.rb, line 1047
1047:       def sql_boolean
1048:         self
1049:       end

|(ce)

Always use an OR operator for | on BooleanExpressions

[Source]

      # File lib/sequel/sql.rb, line 1042
1042:       def |(ce)
1043:         BooleanExpression.new(:OR, self, ce)
1044:       end

Methods

Included Modules

Public Class methods

Public Instance methods