Support cascade deletion

api/s9_demands.py

@@ -1,4 +1,4 @@
-from .operation import *
+from .database import *
 from .s2_junctions import *
 
 def get_demand_schema(name: str) -> dict[str, dict[str, Any]]:
@@ -21,7 +21,7 @@ def get_demand(name: str, junction: str) -> dict[str, Any]:
     return { 'junction': junction, 'demands': ds }
 
 
-def set_demand_cache(name: str, cs: ChangeSet) -> DbChangeSet:
+def set_demand_cmd(name: str, cs: ChangeSet) -> DbChangeSet:
     junction = cs.operations[0]['junction']
     old = get_demand(name, junction)
     new = { 'junction': junction, 'demands': [] }
@@ -55,34 +55,34 @@ def set_demand_cache(name: str, cs: ChangeSet) -> DbChangeSet:
     undo_cs = []
     undo_cs.append(g_update_prefix | { 'type': 'demand' } | old)
 
-    cache = None
+    cmd = None
     if len(cs.operations[0]['demands']) > 0:
         r = cs.operations[0]['demands'][0]
         demand = float(r['demand'])
         pattern = str(r['pattern']) if 'pattern' in r and r['pattern'] != None else None
-        cache = set_junction_cache(name, ChangeSet({'id': junction, 'demand': demand, 'pattern': pattern}))
+        cmd = set_junction_cmd(name, ChangeSet({'id': junction, 'demand': demand, 'pattern': pattern}))
     else:
-        cache = set_junction_cache(name, ChangeSet({'id': junction, 'demand': None, 'pattern': None}))
+        cmd = set_junction_cmd(name, ChangeSet({'id': junction, 'demand': None, 'pattern': None}))
 
     undo_sql = ''
-    if cache != None:
+    if cmd != None:
         redo_sql += '\n'
-        redo_sql += cache.redo_sql
+        redo_sql += cmd.redo_sql
 
-        undo_sql += cache.undo_sql
+        undo_sql += cmd.undo_sql
         undo_sql += '\n'
         undo_sql += _undo_sql
 
-        redo_cs += cache.redo_cs
+        redo_cs += cmd.redo_cs
 
-        undo_cs += cache.undo_cs
+        undo_cs += cmd.undo_cs
         undo_cs.reverse()
 
     return DbChangeSet(redo_sql, undo_sql, redo_cs, undo_cs)
 
 
 def set_demand(name: str, cs: ChangeSet) -> ChangeSet:
-    return execute_command(name, set_demand_cache(name, cs))
+    return execute_command(name, set_demand_cmd(name, cs))
 
 
 class InpDemand:
@@ -152,3 +152,23 @@ def inp_out_demand(name: str) -> list[str]:
         category = f";{obj['category']}" if obj['category'] != None else ';'
         lines.append(f'{junction} {demand} {pattern} {category}')
     return lines
+
+
+def delete_demand_by_junction(name: str, junction: str) -> ChangeSet:
+    row = try_read(name, f"select * from demands where junction = '{junction}'")
+    if row == None:
+        return ChangeSet()
+    return ChangeSet(g_update_prefix | {'type': 'demand', 'junction': junction, 'demands': []})
+
+
+def unset_demand_by_pattern(name: str, pattern: str) -> ChangeSet:
+    cs = ChangeSet()
+
+    rows = read_all(name, f"select distinct id from junctions where pattern = '{pattern}'")
+    for row in rows:
+        ds = get_demand(name, row['id'])
+        for d in ds['demands']:
+            d['pattern'] = None
+        cs.append(g_update_prefix | {'type': 'demand', 'junction': row['junction'], 'demands': ds})
+
+    return cs