Crash of OCIStmtExecute when binding to NULL
Date: Fri, 9 May 2008 16:10:00 +0200
Message-ID: <48245b38$0$7555$9b4e6d93@newsspool1.arcor-online.net>
Hello everyone,
we are currently migrating a software to use Oracle 10 client (OCI) instead of Oracle 9. A problem occurs that manifests itself in form of an application crash and we boiled it down to an OCI snippet which doesnt work anymore. Since I am puzzles I am posting it here, maybe I get some inspiration by you guys...
I am posting the sample code further below but in a nut shell I am doing this:
- Create a table ABC with a single int column.
- Create and prepare a statement INSERT INTO ABC VALUES(:1).
- Bind the :1 to a value, say 8. Execute the statement. Works wonderfully up until here
- Bind the :1 of the same statement to NULL with the intention of inserting a NULL value into the table. No NOT NULL constraint is present.
- Execute the statement again with the new bind --> crash!
- I am using MS Dev Studio 2005, C++, and at the time of the crash the call stack is entirely messed up, no clue to the cause. The message will say: "Unhandled exception at <memory address> in <appl name>: 0xC0000005, Access vilation reading location 0x00000000.
- The very same code used to run perfectly well under Ora9 OCI client.
- The event occurs no matter what database server I use (9 or 10 have been tested).
- The Ora Client is 10.2.0.x.
- If I insert the NULL value first and then 8, it works fine. If I insert the NULL after the 8 with a new statement, not recycling the same prepared statement, it works fine as well!
Thank you very much in advance,
AH
:)
PS: Here is the sample code. The statement that will crash has been marked with a comment.
OCIEnv* _ptrOCIEnvironment; OCIError* _ptrOCIError; OCISvcCtx* _ptrOCIServiceContext;
OCIStmt* _ptrOCIStatement;
sword swdReturnCode;
std::string cmd;
swdReturnCode = OCIEnvCreate(
(OCIEnv**)
&_ptrOCIEnvironment,
(ub4)
OCI_DEFAULT | OCI_THREADED,
(dvoid*) NULL,
(dvoid*(*) (dvoid*, size_t)) NULL,
(dvoid*(*) (dvoid*, dvoid*, size_t)) NULL,
(void(*) (dvoid*, dvoid*)) NULL,
(size_t) 0,
(dvoid**) NULL
);
swdReturnCode = OCIHandleAlloc(
(CONST dvoid*) _ptrOCIEnvironment,
(dvoid **) &_ptrOCIError,
(ub4) OCI_HTYPE_ERROR,
(size_t) 0,
(dvoid **) 0
);
swdReturnCode = OCILogon( (OCIEnv*) _ptrOCIEnvironment, (OCIError*) _ptrOCIError, (OCISvcCtx**) &_ptrOCIServiceContext, (unsigned char*) user.c_str(), (ub4) strlen(user.c_str()), (unsigned char*) pwd.c_str(), (ub4) strlen(pwd.c_str()), (unsigned char*) url.c_str(), (ub4) strlen(url.c_str()) ); swdReturnCode = OCIHandleAlloc( (dvoid *) _ptrOCIEnvironment, //environment handle (dvoid **) &_ptrOCIStatement, //returned handle to the statement (ub4) OCI_HTYPE_STMT, //type of the handle to allocate (size_t) 0, //amount of user memory to be allocated (dvoid **) 0 //pointer to the user memory allocated. );
cmd = "drop table abc";
swdReturnCode = OCIStmtPrepare(
(OCIStmt*) _ptrOCIStatement, //handle to the statement that will be prepared
(OCIError*) _ptrOCIError, //error handle (CONST OraText*) cmd.c_str(), //the SQL statement string (ub4) strlen(cmd.c_str()), //length of the statement string (ub4) OCI_NTV_SYNTAX, //syntax of the statement (ub4) OCI_DEFAULT ); swdReturnCode = OCIStmtExecute( (OCISvcCtx*) _ptrOCIServiceContext, //service context handle (OCIStmt*) _ptrOCIStatement, //statement handle (OCIError*) _ptrOCIError, //error handle (ub4) 1, //the number of times this statement is executed (ub4) 0, //the starting index from which the data in an array bind is relevant for this multiple row execution (CONST OCISnapshot*) NULL, (OCISnapshot *) NULL, (ub4) OCI_DEFAULT );
cmd = "create table abc (a int)";
swdReturnCode = OCIStmtPrepare(
(OCIStmt*) _ptrOCIStatement, //handle to the statement that will be prepared
(OCIError*) _ptrOCIError, //error handle (CONST OraText*) cmd.c_str(), //the SQL statement string (ub4) strlen(cmd.c_str()), //length of the statement string (ub4) OCI_NTV_SYNTAX, //syntax of the statement (ub4) OCI_DEFAULT ); swdReturnCode = OCIStmtExecute( (OCISvcCtx*) _ptrOCIServiceContext, //service context handle (OCIStmt*) _ptrOCIStatement, //statement handle (OCIError*) _ptrOCIError, //error handle (ub4) 1, //the number of times this statement is executed (ub4) 0, //the starting index from which the data in an array bind is relevant for this multiple row execution (CONST OCISnapshot*) NULL, (OCISnapshot *) NULL, (ub4) OCI_DEFAULT );
cmd = "INSERT INTO ABC VALUES(:1)";
swdReturnCode = OCIStmtPrepare(
(OCIStmt*) _ptrOCIStatement, //handle to the statement that will be prepared
(OCIError*) _ptrOCIError, //error handle (CONST OraText*) cmd.c_str(), //the SQL statement string (ub4) strlen(cmd.c_str()), //length of the statement string (ub4) OCI_NTV_SYNTAX, //syntax of the statement (ub4) OCI_DEFAULT );
OCIBind* pBindHandle = NULL;
double dbl = 8.0;
swdReturnCode = OCIBindByPos (
(OCIStmt*) _ptrOCIStatement, (OCIBind**) &pBindHandle, (OCIError*) _ptrOCIError, (ub4) 1, (dvoid*) &dbl, (sb4) sizeof(double), (ub2) SQLT_FLT, (dvoid*) NULL, (ub2*) NULL, (ub2*) NULL, (ub4) NULL, (ub4*) NULL, (ub4) OCI_DEFAULT
);
swdReturnCode = OCIStmtExecute(
(OCISvcCtx*) _ptrOCIServiceContext, //service context handle (OCIStmt*) _ptrOCIStatement, //statement handle (OCIError*) _ptrOCIError, //error handle (ub4) 1, //the number of times this statement is executed (ub4) 0, //the starting index from which the data in an array bind is relevant for this multiple row execution (CONST OCISnapshot*) NULL, (OCISnapshot *) NULL, (ub4) OCI_DEFAULT ); swdReturnCode = OCIBindByPos ( (OCIStmt*) _ptrOCIStatement, (OCIBind**) &pBindHandle, (OCIError*) _ptrOCIError, (ub4) 1, (dvoid*) NULL, (sb4) sizeof(double), (ub2) SQLT_FLT, (dvoid*) NULL, (ub2*) NULL, (ub2*) NULL, (ub4) NULL, (ub4*) NULL, (ub4) OCI_DEFAULT
);
swdReturnCode = OCIStmtExecute(
(OCISvcCtx*) _ptrOCIServiceContext, //service context handle (OCIStmt*) _ptrOCIStatement, //statement handle (OCIError*) _ptrOCIError, //error handle (ub4) 1, //the number of times this statement is executed (ub4) 0, //the starting index from which the data in an array bind is relevant for this multiple row execution (CONST OCISnapshot*) NULL, (OCISnapshot *) NULL, (ub4) OCI_DEFAULT ); swdReturnCode = OCIHandleFree( (dvoid *) _ptrOCIStatement, (ub4) OCI_HTYPE_STMT
);
OCILogoff(_ptrOCIServiceContext, _ptrOCIError); OCIHandleFree((dvoid *) _ptrOCIError, (ub4) OCI_HTYPE_ERROR); OCIHandleFree((dvoid *) _ptrOCIEnvironment, (ub4) OCI_HTYPE_ENV); Received on Fri May 09 2008 - 09:10:00 CDT