fix error message for the case when attempting to delete without the REFERENCE privilege

Author: dimitri-yatsenko

datajoint/autopopulate.py

@@ -98,7 +98,7 @@ def make(self, key):
 
         1. Fetch data from tables above in the dependency hierarchy, restricted by the given key.
         2. Compute secondary attributes based on the fetched data.
-        3. Insert the new tuples into the current table.
+        3. Insert the new tuple(s) into the current table.
 
         The method can be implemented either as:
         (a) Regular method: All three steps are performed in a single database transaction.
@@ -263,9 +263,8 @@ def populate(
             self.connection.schemas[self.target.database].jobs if reserve_jobs else None
         )
 
-        # define and set up signal handler for SIGTERM:
         if reserve_jobs:
-
+            # Define a signal handler for SIGTERM
             def handler(signum, frame):
                 logger.info("Populate terminated by SIGTERM")
                 raise SystemExit("SIGTERM received")

datajoint/declare.py

@@ -302,7 +302,7 @@ def declare(full_table_name, definition, context):
                 name=table_name, max_length=MAX_TABLE_NAME_LENGTH
             )
         )
-
+    
     (
         table_comment,
         primary_key,

datajoint/table.py

@@ -135,7 +135,7 @@ def alter(self, prompt=True, context=None):
         sql, external_stores = alter(self.definition, old_definition, context)
         if not sql:
             if prompt:
-                logger.warn("Nothing to alter.")
+                logger.warning("Nothing to alter.")
         else:
             sql = "ALTER TABLE {tab}\n\t".format(
                 tab=self.full_table_name
@@ -518,7 +518,13 @@ def cascade(table):
                 try:
                     delete_count = table.delete_quick(get_count=True)
                 except IntegrityError as error:
-                    match = foreign_key_error_regexp.match(error.args[0]).groupdict()
+                    match = foreign_key_error_regexp.match(error.args[0])
+                    if match is None:
+                        raise DataJointError(
+                            "Cascading deletes failed because the error message is missing foreign key information."
+                            "Make sure you have REFERENCES privilege to all dependent tables."
+                        ) from None
+                    match = match.groupdict()
                     # if schema name missing, use table
                     if "`.`" not in match["child"]:
                         match["child"] = "{}.{}".format(
@@ -641,7 +647,7 @@ def cascade(table):
         # Confirm and commit
         if delete_count == 0:
             if safemode:
-                logger.warn("Nothing to delete.")
+                logger.warning("Nothing to delete.")
             if transaction:
                 self.connection.cancel_transaction()
         elif not transaction:
@@ -651,12 +657,12 @@ def cascade(table):
                 if transaction:
                     self.connection.commit_transaction()
                 if safemode:
-                    logger.info("Deletes committed.")
+                    logger.info("Delete committed.")
             else:
                 if transaction:
                     self.connection.cancel_transaction()
                 if safemode:
-                    logger.warn("Deletes cancelled")
+                    logger.warning("Delete cancelled")
         return delete_count
 
     def drop_quick(self):
@@ -724,11 +730,6 @@ def size_on_disk(self):
         ).fetchone()
         return ret["Data_length"] + ret["Index_length"]
 
-    def show_definition(self):
-        raise AttributeError(
-            "show_definition is deprecated. Use the describe method instead."
-        )
-
     def describe(self, context=None, printout=False):
         """
         :return:  the definition string for the query using DataJoint DDL.