PostgreSQL 10 : Each sequence does not have 'increment_by' column, ne…

config/initializers/backport_pg_10_support_to_rails_4.rb

@@ -0,0 +1,47 @@
+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.
+#
+# https://github.com/rails/rails/issues/28780#issuecomment-354868174
+#
+
+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