FreeTDS Development Group

[Johnny Yan <jyan AT tableau.com>]

Hi,


We're writing data analytic application on Linux using FreeTDS(0.95.81) with 
unixODBC(2.3.4) to connect to SQL Server databases. Since we need to 
programmatically decide the hosts and other info provided by our customers, 
we decided to use the DSN-less configuration and pass the attributes through 
the connection string. However it seems that we can't set up the client side 
charset correctly.


>From the attached simple sample code, you could see that we could connect 
>with that connection string(you need to change the server and 
>username/password if you want to test it). And we get the following head in 
>the freetds.log file,


log.c:167:Starting log file for FreeTDS 0.95.81
    on 2016-06-30 18:17:32 with debug flags 0x4fff.
iconv.c:328:tds_iconv_open(0xff47a0, UTF-8)
iconv.c:187:local name for ISO-8859-1 is ISO-8859-1
iconv.c:187:local name for UTF-8 is UTF-8
iconv.c:187:local name for UCS-2LE is UCS-2LE
iconv.c:187:local name for UCS-2BE is UCS-2BE
iconv.c:346:setting up conversions for client charset "UTF-8"
iconv.c:348:preparing iconv for "UTF-8" <-> "UCS-2LE" conversion
iconv.c:395:preparing iconv for "ISO-8859-1" <-> "UCS-2LE" conversion


It seems that the client charset is set to UTF-8. Am I correct? My 
understanding is that this is from the LANG env variable since we didn't 
specify it anywhere. Right?


However when we try to specify the charset in the connection string, that is 
appending ";ClientCharset=UTF-16" to the connection string in the sample, we 
didn't observe the expected behavior. In another words, we still see the 
above bold line which implies that the ClientCharset attr in the connection 
string didn't make any difference. Is that expected? Did we do it correctly? 
Probably not. If so, how can we make it right?


Let me know if you need any other info. Thank you very much!


Johnny

#include <stdio.h>
#include <sql.h>
#include <sqlext.h>

main() {
  SQLHENV env;
  SQLHDBC dbc;
  SQLRETURN ret;
  const char instr[] = "DRIVER={FreeTDS};SERVER=servername;PORT=1433;UID=username;PWD=password;Fetch=2048;TDS_Version=auto";
  SQLCHAR outstr[1024];
  SQLSMALLINT outstrlen;

  SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
  SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void *) SQL_OV_ODBC3, 0);
  SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);

  ret = SQLDriverConnect(dbc, NULL, instr, SQL_NTS,
             outstr, sizeof(outstr), &outstrlen,
             SQL_DRIVER_COMPLETE);

  SQLFreeHandle(SQL_HANDLE_DBC, dbc);
  SQLFreeHandle(SQL_HANDLE_ENV, env);
}