Support PostgreSQL 10

1 files changed, 48 insertions, 0 deletions

diff --git a/config/initializers/ar5_pg_10_support.rb b/config/initializers/ar5_pg_10_support.rb
new file mode 100644
index 00000000000..3d8ccd814a8
--- /dev/null
+++ b/config/initializers/ar5_pg_10_support.rb
@@ -0,0 +1,48 @@
+raise "Vendored ActiveRecord 5 code! Delete #{__FILE__}!" if ActiveRecord::VERSION::MAJOR >= 5
+
+require 'active_record/connection_adapters/postgresql/schema_statements'
+
+#
+# Monkey-patch the refused Rails 4.2 patch at https://github.com/rails/rails/pull/31330
+#
+# Updates sequence logic to support PostgreSQL 10.
+#
+# rubocop:disable all
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module SchemaStatements
+        # Resets the sequence of a table's primary key to the maximum value.
+        def reset_pk_sequence!(table, pk = nil, sequence = nil) #:nodoc:
+          unless pk and sequence
+            default_pk, default_sequence = pk_and_sequence_for(table)
+
+            pk ||= default_pk
+            sequence ||= default_sequence
+          end
+
+          if @logger && pk && !sequence
+            @logger.warn "#{table} has primary key #{pk} with no default sequence"
+          end
+
+          if pk && sequence
+            quoted_sequence = quote_table_name(sequence)
+            max_pk = select_value("SELECT MAX(#{quote_column_name pk}) FROM #{quote_table_name(table)}")
+            if max_pk.nil?
+              if postgresql_version >= 100000
+                minvalue = select_value("SELECT seqmin FROM pg_sequence WHERE seqrelid = #{quote(quoted_sequence)}::regclass")
+              else
+                minvalue = select_value("SELECT min_value FROM #{quoted_sequence}")
+              end
+            end
+
+            select_value <<-end_sql, 'SCHEMA'
+              SELECT setval(#{quote(quoted_sequence)}, #{max_pk ? max_pk : minvalue}, #{max_pk ? true : false})
+            end_sql
+          end
+        end
+      end
+    end
+  end
+end
+# rubocop:enable all