Add mqtt-collect script

mqtt-collect

@@ -10,6 +10,14 @@ import datetime
 
 def init_db(path, topics):
     db = sqlite3.connect(path)
+    c = db.cursor()
+    for topic in topics:
+        table = topic.replace('/', '_')
+        c.execute(
+            f'CREATE TABLE IF NOT EXISTS {table} (timestamp timestamp, value real)'
+        )
+
+    db.commit()
     return db
 
 
@@ -37,8 +45,6 @@ def main():
             table = msg.topic.replace("/", "_")
             ts = datetime.datetime.now()
             value = float(msg.payload)
-            c.execute(f'CREATE TABLE IF NOT EXISTS {table} '
-                      '(timestamp timestamp, value real)')
             c.execute(f'INSERT INTO {table} VALUES (?, ?)', (ts, value))
             c.execute(f'SELECT * from {table}')
             db.commit()