cursor.execute() fails when fetching from table with NCLOB column and IS JSON check. · Issue #271 · oracle/python-oracledb (original) (raw)

cursor.execute() crashes when fetching from table with NCLOB column and IS JSON check. The following SQL crashes in Django:

cursor.execute('SELECT * FROM "INSPECTDB_JSONFIELDCOLUMNTYPE" WHERE ROWNUM < 2 AND 2 > 0')

(it works with the 1.4.2 version).

Table definition:

CREATE TABLE "INSPECTDB_JSONFIELDCOLUMNTYPE" ( "ID" NUMBER(11) GENERATED BY DEFAULT ON NULL AS IDENTITY NOT NULL PRIMARY KEY, "JSON_FIELD" NCLOB NOT NULL CHECK ("JSON_FIELD" IS JSON), "NULL_JSON_FIELD" NCLOB NULL CHECK ("NULL_JSON_FIELD" IS JSON) )

  1. What versions are you using?

Oracle 23c (crashes the same way on Oracle 19c).

platform.platform: Linux-5.15.0-89-generic-x86_64-with-glibc2.35
sys.maxsize > 2**32: True
platform.python_version: 3.10.9
oracledb.__version__: 2.0.0
  1. Is it an error or a hang or a crash?

crash

  1. What error(s) or behavior you are seeing?
  File "python3.10/site-packages/oracledb/cursor.py", line 744, in execute
    impl.execute(self)
  File "src/oracledb/impl/thin/cursor.pyx", line 173, in oracledb.thin_impl.ThinCursorImpl.execute
  File "src/oracledb/impl/thin/protocol.pyx", line 425, in oracledb.thin_impl.Protocol._process_single_message
  File "src/oracledb/impl/thin/messages.pyx", line 1323, in oracledb.thin_impl.MessageWithData.postprocess
IndexError: list index out of range
  1. Does your application call init_oracle_client()?

No

  1. Include a runnable Python script that shows the problem.

I was not able to reproduce it with the bare oracledb cursor or Django cursor, but it crashes in our test suite. Maybe previous fetchall(), fetchone(), execute() calls affect it somehow 🤔 🤯