diff --git a/api/command.py b/api/command.py
index 82d72fb..0c3ae5a 100644
--- a/api/command.py
+++ b/api/command.py
@@ -149,8 +149,8 @@ def execute_update_command(name: str, cs: ChangeSet) -> ChangeSet:
         return set_valve(name, cs)
     elif type == _s8_tag:
         return set_tag(name, cs)
-    elif type == _s9_demand: # exception, batch command ...
-        return ChangeSet()
+    elif type == _s9_demand:
+        return set_demand(name, cs)
     elif type == _s10_status:
         return set_status(name, cs)
     elif type == _s11_pattern:
diff --git a/api/parser.py b/api/parser.py
index f3835f5..32cf36b 100644
--- a/api/parser.py
+++ b/api/parser.py
@@ -171,6 +171,10 @@ def _read_inp(inp: str) -> ChangeSet:
         elif name == 'END':
             pass # :)
 
+    # if demand section is empty, fill it with junction data
+    demands_cs = fill_demand(file_cs['JUNCTIONS'], file_cs['DEMANDS'])
+    file_cs['DEMANDS'].merge(demands_cs)
+
     # release file
     file = {}
 
diff --git a/api/s9_demands.py b/api/s9_demands.py
index 8a01848..ea46fea 100644
--- a/api/s9_demands.py
+++ b/api/s9_demands.py
@@ -5,7 +5,7 @@ def get_demand_schema(name: str) -> dict[str, dict[str, Any]]:
     return { 'junction' : {'type': 'str'  , 'optional': False , 'readonly': True },
              'demands'  : {'type': 'list' , 'optional': False , 'readonly': False, 
                            'element': { 'demand'  : {'type': 'float' , 'optional': False , 'readonly': False }, 
-                                        'patten'  : {'type': 'str'   , 'optional': True ,  'readonly': False },
+                                        'pattern'  : {'type': 'str'   , 'optional': True ,  'readonly': False },
                                         'category': {'type': 'str'   , 'optional': True ,  'readonly': False }}}}
 
 
@@ -120,13 +120,37 @@ def inp_in_demand(section: list[str]) -> ChangeSet:
     return cs
 
 
+def fill_demand(junction_cs : ChangeSet, demand_cs : ChangeSet) -> ChangeSet:
+    cs = ChangeSet()
+
+    for j_cs in junction_cs.operations:
+        if 'demand' not in j_cs:
+            continue
+
+        in_demand = False
+        for d_cs in demand_cs.operations:
+            if j_cs['id'] == d_cs['junction']:
+                in_demand = True
+                break
+
+        if not in_demand:
+            obj_cs : dict[str, Any] = g_update_prefix | {'type': 'demand', 'junction' : j_cs['id'], 'demands' : []}
+            j_demand = j_cs['demand']
+            j_pattern = j_cs['pattern'] if 'pattern' in j_cs else None
+            obj_cs['demands'].append({'demand': j_demand, 'pattern' : j_pattern, 'category': None})
+            cs.append(obj_cs)
+
+    return cs
+
+
 def inp_out_demand(name: str) -> list[str]:
     lines = []
     objs = read_all(name, f"select * from demands order by _order")
     for obj in objs:
         junction = obj['junction']
         demand = obj['demand']
-        patten = obj['patten'] if obj['patten'] != None else ''
+        pattern = obj['pattern'] if obj['pattern'] != None else ''
         category = f";{obj['category']}" if obj['category'] != None else ';'
-        lines.append(f'{junction} {demand} {patten} {category}')
+        lines.append(f'{junction} {demand} {pattern} {category}')
+        print(lines[-1])
     return lines