Python always crashes using pydobc connection

Question

I am having a hard time with pyodbc module (python3). The following code always crashes python (I run it from DOS terminal). The crash happens when main() function returns. My data source is a 4D v13 database remote server. I am using 4D-ODBC driver which seems to be properly installed but really not efficient driver. I have disabled SSL connection and my firewall.

class ODBCSource:

    def __init__(self, dsn):
        self.dsn = str(dsn)
        try:
            self.con = pyodbc.connect("dsn={}".format(self.dsn))
            self.cur = self.con.cursor()
            logger.info("ODBC Source DSN='{}' connected.".format(self.dsn))
        except Exception as err:
            self.con = None
            self.cur = None
            logger.error("Cannot connect ODBC Source DSN='{}': {}.".format(self.dsn, err))

    def __bool__(self):
        return not(self.con is None) or not(self.cur is None)

    def __str__(self):
        return "<cripython.dal.ODBCSource id={:#x} dsn='{}'>".format(id(self), self.dsn)

    __repr__ = __str__

# Main Function:
def main():
    db = ODBCSource('CRIPI-4D')

# Program Entry Point:
if(__name__ == "__main__"):
    main()

Windows crash window trace give me the following informations:

Problem signature:
  Problem Event Name:   APPCRASH
  Application Name: python.exe
  Application Version:  0.0.0.0
  Application Timestamp:    5066b7a2
  Fault Module Name:    4DODBC.dll
  Fault Module Version: 14.0.1.0
  Fault Module Timestamp:   53b4d1d6
  Exception Code:   c0000005
  Exception Offset: 00031798
  OS Version:   6.1.7601.2.1.0.256.48
  Locale ID:    2060
  Additional Information 1: 0a9e
  Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
  Additional Information 3: 0a9e
  Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

I have enabled ODBC Trace in order to check what could be wrong with the code. I have found 3 errors in the log.

[...]
odbcsource      1724-2a8    ENTER SQLGetTypeInfo 
        HSTMT               0x0059B1F0
        SWORD                       12 <SQL_VARCHAR>

odbcsource      1724-2a8    EXIT  SQLGetTypeInfo  with return code -1 (SQL_ERROR)
        HSTMT               0x0059B1F0
        SWORD                       12 <SQL_VARCHAR>

        DIAG [24000] [Microsoft][ODBC Driver Manager] Invalid cursor state (0) 

odbcsource      1724-2a8    ENTER SQLGetTypeInfo 
        HSTMT               0x0059B1F0
        SWORD                       -9 <SQL_WVARCHAR>

odbcsource      1724-2a8    EXIT  SQLGetTypeInfo  with return code -1 (SQL_ERROR)
        HSTMT               0x0059B1F0
        SWORD                       -9 <SQL_WVARCHAR>

        DIAG [24000] [Microsoft][ODBC Driver Manager] Invalid cursor state (0) 

odbcsource      1724-2a8    ENTER SQLGetTypeInfo 
        HSTMT               0x0059B1F0
        SWORD                       -2 <SQL_BINARY>

odbcsource      1724-2a8    EXIT  SQLGetTypeInfo  with return code -1 (SQL_ERROR)
        HSTMT               0x0059B1F0
        SWORD                       -2 <SQL_BINARY>

        DIAG [24000] [Microsoft][ODBC Driver Manager] Invalid cursor state (0) 

odbcsource      1724-2a8    ENTER SQLFreeStmt 
        HSTMT               0x0059B1F0
        UWORD                        0 <SQL_CLOSE>
 [...]

By the way, when I run this script from Python IDLE I get no error at all. Does anyone know what is going wrong with this code and how should I solve it?

Howdy, I've had issues with pyodbc version greater than 3.0.7. What version of pyodbc are you using? — FlipperPA, May 12 '15 at 16:15
I am using version 3.0.7, is there a possibility to downgrade? — jlandercy, May 13 '15 at 07:12
Ah, 3.0.7 is the version I use as well. I figured it was worth checking that first. Unfortunately, I'm not familiar with 4D-ODBC. — FlipperPA, May 14 '15 at 07:55

score 0 · Answer 1 · answered Jul 07 '16 at 00:01

An alternative to pyodbc, that could solve you crashing issue, could be to use this native Python Driver for 4D (p4d) that was created by Israel Brewster on Github.

p4d is a Python Database API 2.0 compliant driver for the 4D (4th Dimension) database server. As such, usage should be familiar to anyone who has used any python database modules before. This module is based off of a C library provided by 4D, and integrated with Python using CFFI. As such, installation of this module does require CFFI.

The p4d driver is built off 4D/SQLlib_4D

Python always crashes using pydobc connection

1 Answers1