[Rails51] Pass UniquenessValidationTest#test_validate_case_sensitive_uniqueness

Author: metaskills

lib/active_record/connection_adapters/sqlserver/database_statements.rb

@@ -76,7 +76,7 @@ def release_savepoint(name = current_savepoint_name)
         end
 
         def case_sensitive_comparison(table, attribute, column, value)
-          if value && value.acts_like?(:string)
+          if column.collation && !column.case_sensitive?
             table[attribute].eq(Arel::Nodes::Bin.new(Arel::Nodes::BindParam.new))
           else
             super