diff --git a/src/connector/odbc/tests/tconv.c b/src/connector/odbc/tests/tconv.c
new file mode 100644
index 0000000000000000000000000000000000000000..f0a528cf9a94a3359fdb9b2aaf3983614a30e734
--- /dev/null
+++ b/src/connector/odbc/tests/tconv.c
@@ -0,0 +1,132 @@
+#include "../src/todbc_log.h"
+
+#ifdef _MSC_VER
+#include <winsock2.h>
+#include <windows.h>
+#include "msvcIconv.h"
+#else
+#include <iconv.h>
+#endif
+
+
+#include <stdio.h>
+#include <string.h>
+
+static void usage(const char *arg0);
+static int  do_conv(iconv_t cnv, FILE *fin);
+
+int main(int argc, char *argv[]) {
+  const char *from_enc = "UTF-8";
+  const char *to_enc   = "UTF-8";
+  const char *src      = NULL;
+#ifdef _MSC_VER
+  from_enc = "CP936";
+  to_enc   = "CP936";
+#endif
+  for (int i = 1; i < argc; i++) {
+    const char *arg = argv[i];
+    if (strcmp(arg, "-h") == 0) {
+      usage(argv[0]);
+      return 0;
+    } else if (strcmp(arg, "-f") == 0 ) {
+      i += 1;
+      if (i>=argc) {
+        fprintf(stderr, "expecing <from_enc>, but got nothing\n");
+        return 1;
+      }
+      from_enc = argv[i];
+      continue;
+    } else if (strcmp(arg, "-t") == 0 ) {
+      i += 1;
+      if (i>=argc) {
+        fprintf(stderr, "expecing <to_enc>, but got nothing\n");
+        return 1;
+      }
+      to_enc = argv[i];
+      continue;
+    } else if (arg[0]=='-') {
+      fprintf(stderr, "unknown argument: [%s]\n", arg);
+      return 1;
+    } else {
+      if (src) {
+        fprintf(stderr, "does not allow multiple files\n");
+        return 1;
+      }
+      src = arg;
+      continue;
+    }
+  }
+  FILE *fin = src ? fopen(src, "rb") : stdin;
+  if (!fin) {
+    fprintf(stderr, "failed to open file [%s]\n", src);
+    return 1;
+  }
+  int r = 0;
+  do {
+    iconv_t cnv = iconv_open(to_enc, from_enc);
+    if (cnv == (iconv_t)-1) {
+      fprintf(stderr, "failed to open conv from [%s] to [%s]: [%s]\n", from_enc, to_enc, strerror(errno));
+      return -1;
+    }
+    r = do_conv(cnv, fin);
+    iconv_close(cnv);
+  } while (0);
+  fclose(fin);
+  return r ? 1 : 0;
+}
+
+static void usage(const char *arg0) {
+  fprintf(stderr, "%s -h | [-f <from_enc>] [-t <to_enc>] [file]\n", arg0);
+  return;
+}
+
+#define IN_SIZE     (256*1024)
+#define OUT_SIZE    (8*IN_SIZE)
+static int do_conv(iconv_t cnv, FILE *fin) {
+  int r = 0;
+  char src[IN_SIZE];
+  size_t slen = sizeof(src);
+  char dst[OUT_SIZE];
+  size_t dlen = sizeof(dst);
+  char *start = src;
+  while (!feof(fin)) {
+    slen = (size_t)(src + sizeof(src)  - start);
+    size_t n = fread(start, 1, slen, fin);
+    if (n>0) {
+      char   *ss = src;
+      size_t  sl = n;
+      while (sl) {
+        char   *dd = dst;
+        size_t  dn = dlen;
+        size_t v = iconv(cnv, &ss, &sl, &dd, &dn);
+        if (v==(size_t)-1) {
+          int err = errno;
+          if (err == EILSEQ) {
+            fprintf(stderr, "failed to convert: [%s]\n", strerror(err));
+            r = -1;
+            break;
+          }
+          if (err == EINVAL) {
+            fprintf(stderr, "[%s]\n", strerror(errno));
+            size_t ava = (size_t)(src + sizeof(src) - ss);
+            memcpy(src, ss, ava);
+            start = ss;
+          } else {
+            fprintf(stderr, "internal logic error: [%s]\n", strerror(errno));
+            r = -1;
+            break;
+          }
+        }
+        n = fwrite(dst, 1, (size_t)(dd-dst), stdout);
+        if (n<dd-dst) {
+          fprintf(stderr, "failed to write: [%s]\n", strerror(errno));
+          r = -1;
+          break;
+        }
+      }
+      if (r) break;
+    }
+  }
+  return r ? -1 : 0;
+}
+