Hi,
I have the problem described below in an ODBC application which occurs only
with PostgreSQL and PostgreSQL-ODBC drivers:
When I fetch string data via ODBC of a column with the "text" datatype (but
also when the datatype is "varchar") of a unicode encoded database into a
SQLWCHAR-buffer, the string termination in the out-buffer is set wrong, as only
the first byte of the string-termination is set to 0 (i.e., SQLWCHAR
character at relevant position is 0xcdcd before fetch, and set to 0xcd00 after fetch
instead of 0x000). The problem doesn't occur with other drivers (e.g.,
SQL-Server or SAP-DB/MaxDB).
Details:
--------
- PostgreSQL Server version: 7.3.2-1 running on Windows 2000 under
cygwin-environment
- PostgreSQL-ODBC driver: version: 7-03.02.00
date: 22.10.2003
dll-name: psqlodbc30w.dll
- MS Windows ODBC-Driver Manager
- Create unicode-encoded database with "createdb -E UNICODE unicode" -> ok
- Create "text"-encoded table with "CREATE TABLE unicode(name TEXT)" -> ok
- Insert of string-data: "INSERT INTO unicode(name) VALUES ('Michael')" ->
ok
- Select in the cygwin-shell with "SELECT name FROM unicode" -> ok, returns
one row with "Michael"
- Logfiles attached: psqlodbc_3092.log, mylog_3092.log
When I run the ODBC-Application shown below, the number of bytes returned in
the indicator buffer "nIndOut" by the driver is ok (14), but the
string-termination indicator at position pOutput[8] is set to 0xcd00 instead of 0x0000
(i.e., only first byte is set to 0).
Is this a bug in the driver (as the error doesn't occur with other
ODBC-drivers), or am I doing something wrong? I appriceate your comments on this
problem, as I would like to make our application ready for use with PostgreSQL via
ODBC.
Thanks for your help,
Michael Ziehensack
----------------------------------------------------------
BEGIN OF APPLICATION CODE
----------------------------------------------------------
#include <windows.h>
#include <sqlext.h>
#include <sql.h>
#include <stdio.h>
int main(int argc, char* argv[])
{
SQLRETURN rc = SQL_SUCCESS;
//! allocate environment handle
SQLHENV henv = 0;
rc = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
//! Set the ODBC version environment attribute */
rc = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
//! allocate connection handle
SQLHDBC hdbc = 0;
rc = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
//! ... and set autocommit off
rc = SQLSetConnectAttr(hdbc, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF, 0);
//! Connect to data source */
rc = SQLConnectW(hdbc, (SQLWCHAR*) L"unicode", SQL_NTS,
(SQLWCHAR*) L"ADONIS", SQL_NTS,
(SQLWCHAR*) L"BPMS", SQL_NTS);
//! Allocate statement handle
SQLHSTMT hstmt;
rc = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
SQLWCHAR * pOutput = new SQLWCHAR[100];
SQLINTEGER nIndOut;
SQLINTEGER nCount;
rc = SQLPrepareW (hstmt, (SQLWCHAR*)L"SELECT name FROM unicode", SQL_NTS);
rc = SQLBindCol ( hstmt,
1,
SQL_C_WCHAR,
pOutput,
100,
&nIndOut);
rc = SQLExecute (hstmt);
rc = SQLFetch(hstmt);
/* Error with PostgreSQL-ODBC: driver sets string termination at
relevant position as 0xcd00 (i.e., only the first byte of the
character is set) instead of 0x0000 !!!
*/
nCount = wcslen(pOutput); -> wrong, due to wrong string termination
rc = SQLEndTran (SQL_HANDLE_DBC, hdbc, SQL_ROLLBACK );
//! Free statment handle
rc = SQLFreeHandle(SQL_HANDLE_STMT, hstmt);
//! disconnect
rc = SQLDisconnect(hdbc);
//! Free connection handle
rc = SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
//! Free environment handle
rc = SQLFreeHandle(SQL_HANDLE_ENV, henv);
delete [] pOutput;
return rc;
}
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