1 files changed, 36 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index b2aeb3a058..30df98be1b 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -448,6 +448,42 @@ module ActiveRecord
           execute "ALTER INDEX #{quote_column_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
         end
 
+        def foreign_keys(table_name)
+          fk_info = select_all <<-SQL.strip_heredoc
+            SELECT t2.relname AS to_table, a1.attname AS column, a2.attname AS primary_key, c.conname AS name, c.confupdtype AS on_update, c.confdeltype AS on_delete
+            FROM pg_constraint c
+            JOIN pg_class t1 ON c.conrelid = t1.oid
+            JOIN pg_class t2 ON c.confrelid = t2.oid
+            JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
+            JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
+            JOIN pg_namespace t3 ON c.connamespace = t3.oid
+            WHERE c.contype = 'f'
+              AND t1.relname = #{quote(table_name)}
+              AND t3.nspname = ANY (current_schemas(false))
+            ORDER BY c.conname
+          SQL
+
+          fk_info.map do |row|
+            options = {
+              column: row['column'],
+              name: row['name'],
+              primary_key: row['primary_key']
+            }
+
+            options[:on_delete] = extract_foreign_key_action(row['on_delete'])
+            options[:on_update] = extract_foreign_key_action(row['on_update'])
+            ForeignKeyDefinition.new(table_name, row['to_table'], options)
+          end
+        end
+
+        def extract_foreign_key_action(specifier) # :nodoc:
+          case specifier
+          when 'c'; :cascade
+          when 'n'; :nullify
+          when 'r'; :restrict
+          end
+        end
+
         def index_name_length
           63
         end