From 23cd4d98998101ec65fb364f888054230fbc518a Mon Sep 17 00:00:00 2001
From: Hassan Javeed <hassan@edx.org>
Date: Thu, 19 Sep 2019 21:03:16 +0500
Subject: [PATCH] Management command to add history to
 course_overviews_courseoverview.

---
 ...nerate_initial_history_course_overviews.py | 109 ++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 openedx/core/djangoapps/content/course_overviews/management/commands/generate_initial_history_course_overviews.py

diff --git a/openedx/core/djangoapps/content/course_overviews/management/commands/generate_initial_history_course_overviews.py b/openedx/core/djangoapps/content/course_overviews/management/commands/generate_initial_history_course_overviews.py
new file mode 100644
index 0000000000..6900492b0f
--- /dev/null
+++ b/openedx/core/djangoapps/content/course_overviews/management/commands/generate_initial_history_course_overviews.py
@@ -0,0 +1,109 @@
+"""
+Management command to populate initial history for courseoverview.
+"""
+import logging
+import time
+from django.core.management.base import BaseCommand
+from django.db import connection, transaction
+
+log = logging.getLogger(__name__)
+
+
+class Command(BaseCommand):
+    """
+    Populate initial history for 'courseoverview'.
+    Example usage:
+    $ ./manage.py lms generate_initial_history_course_overviews --batchsize 1000 --sleep_between 1 --settings=devstack
+    """
+
+    help = (
+        "Populates the corresponding historical records with"
+        "the current state of records which do not have a historical record yet"
+    )
+
+    DEFAULT_BATCH_SIZE = 1000
+    DEFAULT_SLEEP_BETWEEN_INSERTS = 1
+    DATE = '2019-06-29'
+    HISTORY_USER_ID = 'NULL'
+    HISTORY_CHANGE_REASON = 'initial history population'
+
+    def add_arguments(self, parser):
+        super(Command, self).add_arguments(parser)
+
+        parser.add_argument(
+            '--sleep_between',
+            default=self.DEFAULT_SLEEP_BETWEEN_INSERTS,
+            type=float,
+            help='Seconds to sleep between chunked inserts.'
+        )
+
+        parser.add_argument(
+            "--batchsize",
+            action="store",
+            default=self.DEFAULT_BATCH_SIZE,
+            type=int,
+            help="Maximum number of history rows to insert in each batch.",
+        )
+
+    def chunks(self, ids, chunk_size):
+        for i in xrange(0, len(ids), chunk_size):
+            yield ids[i:i + chunk_size]
+
+    def handle(self, *args, **options):
+        batch_size = options['batchsize']
+        sleep_between = options['sleep_between']
+
+        with connection.cursor() as cursor:
+            query = u"""
+                SELECT
+                    t.id
+                FROM course_overviews_courseoverview t
+                LEFT JOIN course_overviews_historicalcourseoverview ht
+                    ON t.id = ht.id
+                WHERE ht.id IS NULL
+                """
+            cursor.execute(query)
+            ids_without_history = [rows[0] for rows in cursor.fetchall()]
+
+            if not ids_without_history:
+                log.info(u"No records with missing historical records")
+                return
+            query = u"""
+                SELECT
+                    column_name
+                FROM information_schema.columns
+                WHERE table_name='course_overviews_courseoverview'
+                ORDER BY ordinal_position
+                """
+            cursor.execute(query)
+            columns = [column[0] for column in cursor.fetchall()]
+
+        for chunk in self.chunks(ids_without_history, batch_size):
+            with transaction.atomic():
+                with connection.cursor() as cursor:
+                    # xss-lint: disable=python-wrap-html
+                    query = u"""
+                        INSERT INTO course_overviews_historicalcourseoverview(
+                            {insert_columns},history_date,history_change_reason,history_type,history_user_id
+                        )
+                        SELECT {select_columns},'{history_date}','{history_change_reason}', '+', {history_user_id}
+                        FROM course_overviews_courseoverview t
+                        LEFT JOIN course_overviews_historicalcourseoverview ht
+                            ON t.id=ht.id
+                        WHERE ht.id IS NULL
+                            AND t.id in ({ids})
+                        """.format(
+                            insert_columns=','.join(columns),
+                            select_columns=','.join(['t.{}'.format(c) for c in columns]),
+                            history_date=self.DATE,
+                            history_change_reason=self.HISTORY_CHANGE_REASON,
+                            history_user_id=self.HISTORY_USER_ID,
+                            ids=','.join("'{}'".format(id) for id in chunk)
+                    )
+                    log.info(query)
+                    log.info(u"Starting insert for records with ids: %s", ','.join(chunk))
+                    count = cursor.execute(query)
+                    log.info(u"Inserted %s historical records", count)
+
+            log.info(u"Sleeping %s seconds...", sleep_between)
+            time.sleep(sleep_between)