Add demand api and test

api/s9_demands.py

@@ -0,0 +1,56 @@
+from .operation import *
+from .s0_base import *
+
+
+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 },
+                                        'category': {'type': 'str'   , 'optional': True ,  'readonly': False }}}}
+
+
+def get_demand(name: str, junction: str) -> dict[str, Any]:
+    des = read_all(name, f"select * from demands where junction = '{junction}'")
+    ds = []
+    for r in des:
+        d = {}
+        d['demand'] = float(r['demand'])
+        d['pattern'] = str(r['pattern']) if r['pattern'] != None else None
+        d['category'] = str(r['category']) if r['category'] != None else None
+        ds.append(d)
+    return { 'junction': junction, 'demands': ds }
+
+# { 'operation': 'update', 'type': 'demand', 'junction': 'j1', 'demands': [{'demand': 0.0, 'patten': None, 'category': None}] }
+def set_demand(name: str, cs: ChangeSet) -> ChangeSet:
+    junction = cs.operations[0]['junction']
+    old = get_demand(name, junction)
+    new = { 'junction': junction, 'demands': [] }
+
+    f_junction = f"'{junction}'"
+
+    redo_sql = f"delete from demands where junction = {f_junction};"
+    for r in cs.operations[0]['demands']:
+        demand = float(r['demand'])
+        pattern = str(r['pattern']) if 'pattern' in r and r['pattern'] != None else None
+        category = str(r['category']) if 'category' in r and r['category'] != None else None
+        f_demand = demand
+        f_pattern = f"'{pattern}'" if pattern != None else 'null'
+        f_category = f"'{category}'" if category != None else 'null'
+        redo_sql += f"\ninsert into demands (junction, demand, pattern, category) values ({f_junction}, {f_demand}, {f_pattern}, {f_category});"
+        new['demands'].append({ 'demand': demand, 'pattern': pattern, 'category': category })
+
+    undo_sql = f"delete from demands where junction = {f_junction};"
+    for r in old['demands']:
+        demand = float(r['demand'])
+        pattern = str(r['pattern'])
+        category = str(r['category'])
+        f_demand = demand
+        f_pattern = f"'{pattern}'" if pattern != None else 'null'
+        f_category = f"'{category}'" if category != None else 'null'
+        undo_sql += f"\ninsert into demands (junction, demand, pattern, category) values ({f_junction}, {f_demand}, {f_pattern}, {f_category});"
+    
+    redo_cs = g_update_prefix | { 'type': 'demand' } | new
+    undo_cs = g_update_prefix | { 'type': 'demand' } | old
+
+    return execute_command(name, redo_sql, undo_sql, redo_cs, undo_cs)