Bug report

blobopen internally uses int to hold the requested rowid ([1], [2]), but SQLite rowids are actually 64-bit integers:

int sqlite3_blob_open( sqlite3*, const char *zDb, const char *zTable, const char *zColumn, sqlite3_int64 iRow, // <-- the rowid parameter int flags, sqlite3_blob **ppBlob ); 

This makes an attempt to open a blob with large rowid raise an OverflowError when Python is compiled with 32-bit int, which is the case on Windows even when compiling as 64-bit application.

This might seem like an edge case, but any INTEGER PRIMARY KEY in a rowid table aliases rowid, which means any application that uses non-autoincrement primary keys (e.g. timestamps, checksums) is likely to hit this very trivially -- I know I did on basically the first insert. You don't need to have more than 2**32 rows or anything like that for this to happen.

100% reproducible with:

import sqlite3 con = sqlite3.connect(':memory:') rowid = 2**32 con.execute("create table t(t blob)") con.execute("insert into t(rowid, t) values (?, zeroblob(1))", (rowid,)) con.blobopen('t', 't', rowid)

Expected: nothing (i.e. successful call)
Instead:

Traceback (most recent call last): File "E:\Temp\blob.py", line 10, in <module> con.blobopen('t', 't', rowid) OverflowError: Python int too large to convert to C int 

Your environment

• CPython versions tested on: 3.11.0 (main, Oct 24 2022, 18:26:48) [MSC v.1933 64 bit (AMD64)], 3.12.0a3+ (heads/main-dirty:cb60b6131b, Dec 20 2022, 14:37:41) [MSC v.1934 64 bit (AMD64)]
• Operating system and architecture: Windows x64

Linked PRs

• gh-100370: fix OverflowError in sqlite3.Connection.blobopen for 32-bit builds #103902
• [3.11] gh-100370: fix OverflowError in sqlite3.Connection.blobopen for 32-bit builds (#103902) #104285