SQLBindParameter() does not work with UTF-8 ?!
Norbert Matzke <[email protected]>
| Newsgroups | gmane.comp.db.tds.freetds |
|---|---|
| Message-ID | <[email protected]> |
Problem: My client ODBC application needs to bind parameters which are UTF-8 encoded to SQL insert/update statements. I have set ClientCharset to UTF-8 in freetds.conf. I did some tests with Version 0.82 of FreeTDS and SQL Server 2005. Seemed to work, but not with a short UTF-8 String like '€'. '€' is 3 bytes long in UTF-8 encoding. If I called SQLBindParameter( , ,SQL_C_CHAR, SQL_WVARCHAR, n, 0, , , &ind ) with n=1 and *ind=3 I got an error message. iconv was not able to convert '€' and SQL Server complains also ... Calling with n=3 and *ind=3 succeeds but inserts the string '€ ' into the database because the Server pads with 2 blanks to the requested size of 3 CHARS. Setting *ind=SQL_NTS did not help. I have tested version 0.83dev 2008-10-09 also: It did not work at all using UTF-8 strings with non single byte UTF-8 characters. So I have had a look at what is going on inside the FreeTDS code (ver. 0.83dev) and found that the problem arises due to insufficient buffer space for the bounded parameter. I solved the problem with very small changes to tds/mem.c and odbc/sql2tds.c (see attached patch). For me it works now. Any comments on this issue ? Best regards, Norbert _______________________________________________ FreeTDS mailing list [email protected] http://lists.ibiblio.org/mailman/listinfo/freetds
patch_freetds_0.83dev20081009.diff
(text/x-patch, 2.1 KB)
diff -r -b -B -U 5 freetds-0.83.dev.20081009/src/odbc/sql2tds.c freetds-0.83.dev.20081009_patched/src/odbc/sql2tds.c
--- freetds-0.83.dev.20081009/src/odbc/sql2tds.c 2008-09-11 17:09:50.000000000 +0200
+++ freetds-0.83.dev.20081009_patched/src/odbc/sql2tds.c 2008-10-10 14:42:35.000000000 +0200
@@ -296,10 +296,17 @@
curcol->column_cur_size = -1;
return SQL_SUCCESS;
}
}
+ /* will be re-set after tds_convert(), but we need enough space for utf-8 strings and
+ column_size is currently set to SQLBindParmeter::ColumnSize, which is the number
+ of displayable/encoded chars in case of NVARCHAR, ... columns, not the number of utf-8 bytes !
+ tds_alloc_param() changed to allocate max( column_size, column_cur_size )
+ */
+ if (len > 0) curcol->column_cur_size = len;
+
/* allocate given space */
if (!tds_alloc_param_data(curcol)) {
odbc_errs_add(&stmt->errs, "HY001", NULL);
return SQL_ERROR;
}
@@ -348,14 +355,12 @@
case XSYBVARCHAR:
case XSYBNVARCHAR:
case XSYBNCHAR:
case SYBNVARCHAR:
ores.cc.c = (TDS_CHAR*) dest;
- ores.cc.len = curcol->column_size;
+ ores.cc.len = curcol->column_cur_size; /* see modified tds_alloc_param_data() */
res = tds_convert(dbc->env->tds_ctx, src_type, src, len, TDS_CONVERT_CHAR, &ores);
- if (res > curcol->column_size)
- res = curcol->column_size;
break;
case SYBBINARY:
case SYBVARBINARY:
case XSYBBINARY:
case XSYBVARBINARY:
diff -r -b -B -U 5 freetds-0.83.dev.20081009/src/tds/mem.c freetds-0.83.dev.20081009_patched/src/tds/mem.c
--- freetds-0.83.dev.20081009/src/tds/mem.c 2008-09-14 09:45:25.000000000 +0200
+++ freetds-0.83.dev.20081009_patched/src/tds/mem.c 2008-10-10 13:47:41.000000000 +0200
@@ -274,11 +274,12 @@
if (is_numeric_type(curparam->column_type)) {
data_size = sizeof(TDS_NUMERIC);
} else if (is_blob_type(curparam->column_type)) {
data_size = sizeof(TDSBLOB);
} else {
- data_size = curparam->column_size;
+ data_size = curparam->column_cur_size > curparam->column_size ?
+ curparam->column_cur_size : curparam->column_size;
}
/* allocate data */
if (curparam->column_data && curparam->column_data_free)