1 files changed, 36 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb
index ceb8b40bd9..84dd28907b 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_creation.rb
@@ -17,6 +17,42 @@ module ActiveRecord
             "VALIDATE CONSTRAINT #{quote_column_name(name)}"
           end
 
+          def visit_ChangeColumnDefinition(o)
+            column = o.column
+            column.sql_type = type_to_sql(column.type, column.options)
+            quoted_column_name = quote_column_name(o.name)
+
+            change_column_sql = +"ALTER COLUMN #{quoted_column_name} TYPE #{column.sql_type}"
+
+            options = column_options(column)
+
+            if options[:collation]
+              change_column_sql << " COLLATE \"#{options[:collation]}\""
+            end
+
+            if options[:using]
+              change_column_sql << " USING #{options[:using]}"
+            elsif options[:cast_as]
+              cast_as_type = type_to_sql(options[:cast_as], options)
+              change_column_sql << " USING CAST(#{quoted_column_name} AS #{cast_as_type})"
+            end
+
+            if options.key?(:default)
+              if options[:default].nil?
+                change_column_sql << ", ALTER COLUMN #{quoted_column_name} DROP DEFAULT"
+              else
+                quoted_default = quote_default_expression(options[:default], column)
+                change_column_sql << ", ALTER COLUMN #{quoted_column_name} SET DEFAULT #{quoted_default}"
+              end
+            end
+
+            if options.key?(:null)
+              change_column_sql << ", ALTER COLUMN #{quoted_column_name} #{options[:null] ? 'DROP' : 'SET'} NOT NULL"
+            end
+
+            change_column_sql
+          end
+
           def add_column_options!(sql, options)
             if options[:collation]
               sql << " COLLATE \"#{options[:collation]}\""