Merge pull request #15606 from senny/ar/foreign_key_support

Basic support for adding and removing foreign keys

1 files changed, 39 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index e055d571ab..64bc68eefd 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -91,7 +91,8 @@ HEADER
       end
 
       def tables(stream)
-        @connection.tables.sort.each do |tbl|
+        sorted_tables = @connection.tables.sort
+        sorted_tables.each do |tbl|
           next if ['schema_migrations', ignore_tables].flatten.any? do |ignored|
             case ignored
             when String; remove_prefix_and_suffix(tbl) == ignored
@@ -102,6 +103,13 @@ HEADER
           end
           table(tbl, stream)
         end
+
+        # dump foreign keys at the end to make sure all dependent tables exist.
+        if @connection.supports_foreign_keys?
+          sorted_tables.each do |tbl|
+            foreign_keys(tbl, stream)
+          end
+        end
       end
 
       def table(table, stream)
@@ -212,6 +220,36 @@ HEADER
         end
       end
 
+      def foreign_keys(table, stream)
+        if (foreign_keys = @connection.foreign_keys(table)).any?
+          add_foreign_key_statements = foreign_keys.map do |foreign_key|
+            parts = [
+                     'add_foreign_key ' + remove_prefix_and_suffix(foreign_key.from_table).inspect,
+                     remove_prefix_and_suffix(foreign_key.to_table).inspect,
+                    ]
+
+            if foreign_key.column != @connection.foreign_key_column_for(foreign_key.to_table)
+              parts << ('column: ' + foreign_key.column.inspect)
+            end
+
+            if foreign_key.custom_primary_key?
+              parts << ('primary_key: ' + foreign_key.primary_key.inspect)
+            end
+
+            if foreign_key.name !~ /^fk_rails_[0-9a-f]{10}$/
+              parts << ('name: ' + foreign_key.name.inspect)
+            end
+
+            parts << ('on_update: ' + foreign_key.on_update.inspect) if foreign_key.on_update
+            parts << ('on_delete: ' + foreign_key.on_delete.inspect) if foreign_key.on_delete
+
+            '  ' + parts.join(', ')
+          end
+
+          stream.puts add_foreign_key_statements.sort.join("\n")
+        end
+      end
+
       def remove_prefix_and_suffix(table)
         table.gsub(/^(#{@options[:table_name_prefix]})(.+)(#{@options[:table_name_suffix]})$/,  "\\2")
       end