Index: 20091227112908_change_wiki_contents_text_limit.rb
===================================================================
--- 20091227112908_change_wiki_contents_text_limit.rb	(revision 18254)
+++ 20091227112908_change_wiki_contents_text_limit.rb	(working copy)
@@ -3,7 +3,7 @@
     # Migrates MySQL databases only
     # Postgres would raise an error (see http://dev.rubyonrails.org/ticket/3818)
     # Not fixed in Rails 2.3.5
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :wiki_contents, :text, :text, :limit => max_size
       change_column :wiki_content_versions, :data, :binary, :limit => max_size
Index: 20140228130325_change_changesets_comments_limit.rb
===================================================================
--- 20140228130325_change_changesets_comments_limit.rb	(revision 18254)
+++ 20140228130325_change_changesets_comments_limit.rb	(working copy)
@@ -1,6 +1,6 @@
 class ChangeChangesetsCommentsLimit < ActiveRecord::Migration[4.2]
   def up
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :changesets, :comments, :text, :limit => max_size
     end
Index: 20161010081301_change_issues_description_limit.rb
===================================================================
--- 20161010081301_change_issues_description_limit.rb	(revision 18254)
+++ 20161010081301_change_issues_description_limit.rb	(working copy)
@@ -1,6 +1,6 @@
 class ChangeIssuesDescriptionLimit < ActiveRecord::Migration[4.2]
   def up
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :issues, :description, :text, :limit => max_size
     end
Index: 20161010081528_change_journal_details_value_limit.rb
===================================================================
--- 20161010081528_change_journal_details_value_limit.rb	(revision 18254)
+++ 20161010081528_change_journal_details_value_limit.rb	(working copy)
@@ -1,6 +1,6 @@
 class ChangeJournalDetailsValueLimit < ActiveRecord::Migration[4.2]
   def up
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :journal_details, :value, :text, :limit => max_size
       change_column :journal_details, :old_value, :text, :limit => max_size
Index: 20161010081600_change_journals_notes_limit.rb
===================================================================
--- 20161010081600_change_journals_notes_limit.rb	(revision 18254)
+++ 20161010081600_change_journals_notes_limit.rb	(working copy)
@@ -1,6 +1,6 @@
 class ChangeJournalsNotesLimit < ActiveRecord::Migration[4.2]
   def up
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :journals, :notes, :text, :limit => max_size
     end
Index: 20170320051650_change_repositories_extra_info_limit.rb
===================================================================
--- 20170320051650_change_repositories_extra_info_limit.rb	(revision 18254)
+++ 20170320051650_change_repositories_extra_info_limit.rb	(working copy)
@@ -1,6 +1,6 @@
 class ChangeRepositoriesExtraInfoLimit < ActiveRecord::Migration[4.2]
   def up
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :repositories, :extra_info, :text, :limit => max_size
     end
Index: 20190315094151_change_custom_values_value_limit.rb
===================================================================
--- 20190315094151_change_custom_values_value_limit.rb	(revision 18254)
+++ 20190315094151_change_custom_values_value_limit.rb	(working copy)
@@ -1,6 +1,6 @@
 class ChangeCustomValuesValueLimit < ActiveRecord::Migration[5.2]
   def up
-    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+    if Redmine::Database.mysql?
       max_size = 16.megabytes
       change_column :custom_values, :value, :text, :limit => max_size
     end