diff --git a/api/s11_patterns.py b/api/s11_patterns.py
index d7d1417..96e6ce2 100644
--- a/api/s11_patterns.py
+++ b/api/s11_patterns.py
@@ -7,7 +7,7 @@ def get_pattern_schema(name: str) -> dict[str, dict[str, Any]]:
 
 
 def get_pattern(name: str, id: str) -> dict[str, Any]:
-    pas = read_all(name, f"select * from patterns where id = '{id}'")
+    pas = read_all(name, f"select * from patterns where id = '{id}' order by _order")
     ps = []
     for r in pas:
         ps.append(float(r['factor']))
diff --git a/api/s12_curves.py b/api/s12_curves.py
index a10299b..4edc159 100644
--- a/api/s12_curves.py
+++ b/api/s12_curves.py
@@ -9,7 +9,7 @@ def get_curve_schema(name: str) -> dict[str, dict[str, Any]]:
 
 
 def get_curve(name: str, id: str) -> dict[str, Any]:
-    cus = read_all(name, f"select * from curves where id = '{id}'")
+    cus = read_all(name, f"select * from curves where id = '{id}' order by _order")
     cs = []
     for r in cus:
         cs.append({ 'x': float(r['x']), 'y': float(r['y']) })
diff --git a/api/s7_valves.py b/api/s7_valves.py
index 8c21447..4a24b1a 100644
--- a/api/s7_valves.py
+++ b/api/s7_valves.py
@@ -119,15 +119,4 @@ def delete_valve_cache(name: str, cs: ChangeSet) -> SqlChangeSet:
 
 
 def delete_valve(name: str, cs: ChangeSet) -> ChangeSet:
-    old = Valve(get_valve(name, cs.operations[0]['id']))
-
-    redo_sql = f"delete from valves where id = {old.f_id};"
-    redo_sql += f"\ndelete from _link where id = {old.f_id};"
-
-    undo_sql = f"insert into _link (id, type) values ({old.f_id}, {old.f_type});"
-    undo_sql += f"\ninsert into valves (id, node1, node2, diameter, type, setting, minor_loss) values ({old.f_id}, {old.f_node1}, {old.f_node2}, {old.f_diameter}, {old.f_v_type}, {old.f_setting}, {old.f_minor_loss});"
-
-    redo_cs = g_delete_prefix | old.as_id_dict()
-    undo_cs = g_add_prefix | old.as_dict()
-
     return execute_command(name, delete_valve_cache(name, cs))
diff --git a/api/s9_demands.py b/api/s9_demands.py
index 07cc262..77518c1 100644
--- a/api/s9_demands.py
+++ b/api/s9_demands.py
@@ -10,7 +10,7 @@ def get_demand_schema(name: str) -> dict[str, dict[str, Any]]:
 
 
 def get_demand(name: str, junction: str) -> dict[str, Any]:
-    des = read_all(name, f"select * from demands where junction = '{junction}'")
+    des = read_all(name, f"select * from demands where junction = '{junction}' order by _order")
     ds = []
     for r in des:
         d = {}
diff --git a/script/sql/create/11.patterns.sql b/script/sql/create/11.patterns.sql
index 8835fa2..d77671f 100644
--- a/script/sql/create/11.patterns.sql
+++ b/script/sql/create/11.patterns.sql
@@ -2,6 +2,7 @@
 
 create table patterns
 (
-  id varchar(32) references _pattern(id) not null
+  _order serial primary key
+, id varchar(32) references _pattern(id) not null
 , factor numeric not null
 );
diff --git a/script/sql/create/12.curves.sql b/script/sql/create/12.curves.sql
index 11ae78b..bbc05a1 100644
--- a/script/sql/create/12.curves.sql
+++ b/script/sql/create/12.curves.sql
@@ -2,7 +2,8 @@
 
 create table curves
 (
-  id varchar(32) references _curve(id) not null
+  _order serial primary key
+, id varchar(32) references _curve(id) not null
 , x numeric not null
 , y numeric not null
 );
diff --git a/script/sql/create/9.demands.sql b/script/sql/create/9.demands.sql
index d2d2943..13c5b5e 100644
--- a/script/sql/create/9.demands.sql
+++ b/script/sql/create/9.demands.sql
@@ -2,7 +2,8 @@
 
 create table demands
 (
-  junction varchar(32) references junctions(id) not null
+  _order serial primary key
+, junction varchar(32) references junctions(id) not null
 , demand numeric not null
 , pattern varchar(32) references _pattern(id)
 , category text