[1.9.x] Fixed #26063 -- Crash when passing > 2000 params.

If SQLITE_MAX_VARIABLE_NUMBER (default = 999) is changed at compile time
to be greater than SQLITE_MAX_COLUMN (default = 2000), which Debian does
by setting the former to 250000, Django raised an exception on queries
containing more than 2000 parameters when DEBUG = True.

Backport of f91b5a7e4b from master

1 files changed, 13 insertions, 0 deletions

diff --git a/django/db/backends/sqlite3/operations.py b/django/db/backends/sqlite3/operations.py
index 91d1a27f8a..1a4f4baa6c 100644
--- a/django/db/backends/sqlite3/operations.py
+++ b/django/db/backends/sqlite3/operations.py
@@ -107,6 +107,19 @@ class DatabaseOperations(BaseDatabaseOperations):
         """
         Only for last_executed_query! Don't use this to execute SQL queries!
         """
+        # This function is limited both by SQLITE_LIMIT_VARIABLE_NUMBER (the
+        # number of paramters, default = 999) and SQLITE_MAX_COLUMN (the
+        # number of return values, default = 2000). Since Python's sqlite3
+        # module doesn't expose the get_limit() C API, assume the default
+        # limits are in effect and split the work in batches if needed.
+        BATCH_SIZE = 999
+        if len(params) > BATCH_SIZE:
+            results = ()
+            for index in range(0, len(params), BATCH_SIZE):
+                chunk = params[index:index + BATCH_SIZE]
+                results += self._quote_params_for_last_executed_query(chunk)
+            return results
+
         sql = 'SELECT ' + ', '.join(['QUOTE(?)'] * len(params))
         # Bypass Django's wrappers and use the underlying sqlite3 connection
         # to avoid logging this query - it would trigger infinite recursion.