owsql: Try to create missing extensions

Orange/widgets/data/owsql.py

@@ -15,6 +15,7 @@
 
 
 MAX_DL_LIMIT = 1000000
+EXTENSIONS = ('tsm_system_time', 'quantile')
 
 
 class OWSql(widget.OWWidget):
@@ -176,6 +177,7 @@ def connect(self):
 
     def refresh_tables(self):
         self.tablecombo.clear()
+        [self.error(42 + i) for i in range(len(EXTENSIONS))]
         if self._connection is None:
             self.data_desc_table = None
             return
@@ -215,7 +217,19 @@ def select_table(self):
             self.database_desc["Table"] = "(None)"
             self.table = None
 
+    def create_extensions(self):
+        for i, ext in enumerate(EXTENSIONS):
+            try:
+                cur = self._connection.cursor()
+                cur.execute("CREATE EXTENSION IF NOT EXISTS " + ext)
+                self.error(42 + i)
+            except psycopg2.OperationalError:
+                self.error(42 + i, 'Database missing extension ' + ext)
+            finally:
+                self._connection.commit()
+
     def open_table(self):
+        self.create_extensions()
         table = self.get_table()
         self.data_desc_table = table
         self.send("Data", table)