Methods
Public Class
Public Instance
Attributes
| conditions | [R] |
An array of all two pairs with the first element specifying the condition and the second element specifying the result if the condition matches. |
| default | [R] |
The default value if no conditions match. |
| expression | [R] |
An optional expression to test the conditions against |
Public Class methods
new(conditions, default, expression=(no_expression=true; nil))
Create an object with the given conditions and default value, and optional expression. An expression can be provided to test each condition against, instead of having all conditions represent their own boolean expression.
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# File lib/sequel/sql.rb 1217 def initialize(conditions, default, expression=(no_expression=true; nil)) 1218 raise(Sequel::Error, 'CaseExpression conditions must be a hash or array of all two pairs') unless Sequel.condition_specifier?(conditions) 1219 @conditions = conditions.to_a.dup.freeze 1220 @default = default 1221 @expression = expression 1222 @no_expression = no_expression 1223 freeze 1224 end
Public Instance methods
expression?()
Whether to use an expression for this CASE expression.
[show source]
# File lib/sequel/sql.rb 1227 def expression? 1228 !@no_expression 1229 end
with_merged_expression()
Merge the CASE expression into the conditions, useful for databases that don’t support CASE expressions.
[show source]
# File lib/sequel/sql.rb 1233 def with_merged_expression 1234 if expression? 1235 e = expression 1236 CaseExpression.new(conditions.map{|c, r| [::Sequel::SQL::BooleanExpression.new(:'=', e, c), r]}, default) 1237 else 1238 self 1239 end 1240 end