Constant SELECT_BLOBS_SQL 

pub const SELECT_BLOBS_SQL: &str = r#"
SELECT bl.channel, bl.type, bl.blob
FROM checkpoints cp
CROSS JOIN json_each(json_extract(cp.checkpoint, '$.channel_versions')) je
INNER JOIN checkpoint_blobs bl
    ON bl.thread_id = cp.thread_id
    AND bl.checkpoint_ns = cp.checkpoint_ns
    AND bl.channel = je.key
    AND bl.version = CAST(je.value AS TEXT)
WHERE cp.thread_id = ?1
  AND cp.checkpoint_ns = ?2
  AND cp.checkpoint_id = ?3
"#;

Fetch all blobs (channel values) for a given checkpoint by joining checkpoint.channel_versions with the blobs table.

SQLite stores version as TEXT, while je.value from json_each may be a JSON number or string depending on how the checkpoint was produced. The explicit CAST(... AS TEXT) normalizes both sides so integer and string versions compare equal.