Query sqlite_master in ensure_insert_time_column()

scrapy · Jul 3, 2019 · 0343475 · 0343475
1 parent 631fd44
commit 0343475
Showing 1 changed file with 7 additions and 16 deletions.
diff --git a/scrapyd/sqlite.py b/scrapyd/sqlite.py
@@ -148,22 +148,13 @@ def clear(self):
         self.update_project_priority_map()
 
     def ensure_insert_time_column(self):
-        q = "SELECT insert_time FROM %s LIMIT 1" % self.table
-        try:
-            self.conn.execute(q).fetchone()
-        except sqlite3.OperationalError as err:
-            # sqlite3.OperationalError: no such column: insert_time
-            if 'insert_time' in str(err):
-                # Cannot append 'DEFAULT CURRENT_TIMESTAMP' when ALTER TABLE, otherwise,
-                # would raise sqlite3.OperationalError: Cannot add a column with non-constant default
-                q = "ALTER TABLE %s ADD COLUMN insert_time TIMESTAMP" % self.table
-                self.conn.execute(q)
-                # Fill in the new added column for exsiting pending jobs
-                q = "UPDATE %s SET insert_time=CURRENT_TIMESTAMP" % self.table
-                self.conn.execute(q)
-                self.conn.commit()
-            else:
-                raise
+        q = "SELECT sql FROM sqlite_master WHERE type='table' AND name='%s'" % self.table
+        if 'insert_time TIMESTAMP' not in self.conn.execute(q).fetchone()[0]:
+            q = "ALTER TABLE %s ADD COLUMN insert_time TIMESTAMP" % self.table
+            self.conn.execute(q)
+            q = "UPDATE %s SET insert_time=CURRENT_TIMESTAMP" % self.table
+            self.conn.execute(q)
+            self.conn.commit()
 
     def update_project_priority_map(self):
         q = "select priority, strftime('%%s', insert_time) from %s order by priority desc limit 1" \