Index: database.rb
===================================================================
--- database.rb	(revision 17354)
+++ database.rb	(working copy)
@@ -21,7 +21,7 @@
     class << self
       # Returns true if the database is PostgreSQL
       def postgresql?
-        (ActiveRecord::Base.connection.adapter_name =~ /postgresql/i).present?
+        /postgresql/i.match?(ActiveRecord::Base.connection.connection.adapter_name)
       end
 
       # Returns the PostgreSQL version or nil if another DBMS is used
@@ -46,7 +46,7 @@
 
       # Returns true if the database is MySQL
       def mysql?
-        (ActiveRecord::Base.connection.adapter_name =~ /mysql/i).present?
+        /mysql/i.match?(ActiveRecord::Base.connection.connection.adapter_name)
       end
 
       # Returns a SQL statement for case/accent (if possible) insensitive match
Index: nested_set/issue_nested_set.rb
===================================================================
--- nested_set/issue_nested_set.rb	(revision 17354)
+++ nested_set/issue_nested_set.rb	(working copy)
@@ -84,7 +84,7 @@
         if parent
           previous_root_id = root_id
           self.root_id = parent.root_id
-          
+
           lft_after_move = target_lft
           self.class.where(:root_id => parent.root_id).update_all([
             "lft = CASE WHEN lft >= :lft THEN lft + :shift ELSE lft END, " +
@@ -91,12 +91,12 @@
             "rgt = CASE WHEN rgt >= :lft THEN rgt + :shift ELSE rgt END",
             {:lft => lft_after_move, :shift => (rgt - lft + 1)}
           ])
-    
+
           self.class.where(:root_id => previous_root_id).update_all([
             "root_id = :root_id, lft = lft + :shift, rgt = rgt + :shift",
             {:root_id => parent.root_id, :shift => lft_after_move - lft}
           ])
-    
+
           self.lft, self.rgt = lft_after_move, (rgt - lft + lft_after_move)
           parent.send :reload_nested_set_values
         end
@@ -105,7 +105,7 @@
       def remove_from_nested_set
         self.class.where(:root_id => root_id).where("lft >= ? AND rgt <= ?", lft, rgt).
           update_all(["root_id = :id, lft = lft - :shift, rgt = rgt - :shift", {:id => id, :shift => lft - 1}])
-    
+
         self.class.where(:root_id => root_id).update_all([
           "lft = CASE WHEN lft >= :lft THEN lft - :shift ELSE lft END, " +
           "rgt = CASE WHEN rgt >= :lft THEN rgt - :shift ELSE rgt END",
@@ -149,7 +149,7 @@
       end
 
       def lock_nested_set
-        if self.class.connection.adapter_name =~ /sqlserver/i
+        if /sqlserver/i.match?(self.class.connection.adapter_name)
           lock = "WITH (ROWLOCK HOLDLOCK UPDLOCK)"
           # Custom lock for SQLServer
           # This can be problematic if root_id or parent root_id changes
Index: nested_set/project_nested_set.rb
===================================================================
--- nested_set/project_nested_set.rb	(revision 17354)
+++ nested_set/project_nested_set.rb	(working copy)
@@ -119,7 +119,7 @@
 
       def lock_nested_set
         lock = true
-        if self.class.connection.adapter_name =~ /sqlserver/i
+        if /sqlserver/i.match?(self.class.connection.adapter_name)
           lock = "WITH (ROWLOCK HOLDLOCK UPDLOCK)"
         end
         self.class.order(:id).lock(lock).ids