How to execute multi parameter ODBC command by C++ - odbc

Question

I'm working on an ODBC program that needs to store two types of long data: nvarchar (max) and nvarbinary (max). It works well when I do it with one parameter, but it gives an error for two parameters. secound loop for SQL_NEED_DATA gives odbc error
ERROR ==> [ODBC SQL Server Driver]Invalid character value for cast specification
.My code is as follows:
bool ExecuteQuery(wstring const& command_text,vector<void*> params)
{
SQLWCHAR* blob = nullptr;// (SQLWCHAR*)params[0];
SQLSMALLINT NumParams;
SQLSMALLINT i, sql_type, decimals, nullable, paramNo;
SQLULEN bytes;
RETCODE retcode;
SQLLEN cbTextSize, valueMax = 0;
vector<SQLLEN> lbytes;
PTR pParamID;
SQLLEN len;
vector<SDWORD> cbBatch;
SQLPOINTER pToken = NULL;
retcode = SQLPrepare(hstmt, (SQLWCHAR*)command_text.c_str(), SQL_NTS);
//Get number of parameters
SQLNumParams(hstmt, &NumParams);
for (i = 0; i < NumParams; i++)
{
size_t length = wcslen((wchar_t*)params[i]);
//This ia important to save all data to sql table
size_t size = length * sizeof(wchar_t);
len = SQL_LEN_DATA_AT_EXEC((SQLLEN)size);
retcode = SQLDescribeParam(hstmt, i + 1, &sql_type, &bytes, &decimals, &nullable);
//SQL_C_WCHAR for hex binary data in wchar_t and SQL_WLONGVARCHAR succeeded
short c_type = map_datatype_SQL_to_C(sql_type);
retcode = SQLBindParameter(hstmt, i + 1, INPUT, c_type, sql_type, bytes, decimals, (PTR)(1+i), 0, &len);
}
//Execute the insert query.
retcode = SQLExecute(hstmt);
// Check for EOD marker.
retcode = SQLParamData(hstmt, &pToken);
//Loop, sending the data in segments of 124
int buffer_size = sizeof(wchar_t);
int chunk = 124;
for (i = 0; i < NumParams; i++)
{
size_t length = wcslen((wchar_t*)params[i]);
blob = (wchar_t*)params[i];
while (retcode == SQL_NEED_DATA)
{
while (length > chunk)
{
retcode = SQLPutData(hstmt, blob, static_cast<SQLLEN>(chunk * buffer_size));
extract_error("", hstmt, SQL_HANDLE_STMT);
blob += chunk;
length -= chunk;
}
retcode = SQLPutData(hstmt, blob, length * buffer_size);
extract_error("", hstmt, SQL_HANDLE_STMT);
}
retcode = SQLParamData(hstmt, &pToken);
}
return SQL_SUCCEEDED(retcode);
}
short map_datatype_SQL_to_C(short sql_type)
{
switch (sql_type)
{
case SQL_TINYINT:return SQL_C_TINYINT;
case SQL_LONGVARBINARY://-4
case SQL_VARBINARY://-3
case SQL_WLONGVARCHAR://-10
case SQL_WVARCHAR: //-9
case SQL_WCHAR: //-8
return SQL_C_WCHAR;// = SQL_C_TCHAR -8
case SQL_BIT:return SQL_C_BIT;
case SQL_BINARY://-2
return SQL_C_BINARY;
case SQL_DOUBLE://8 - FLOAT, DOUBLE
return SQL_C_DOUBLE;
case SQL_SMALLINT://5
return SQL_C_SHORT;
case SQL_FLOAT://6
case SQL_REAL: //7
return SQL_C_FLOAT;//7
case SQL_INTEGER://4
return SQL_C_LONG;
case SQL_CHAR://1
case SQL_VARCHAR://12
case SQL_DECIMAL://3
case SQL_NUMERIC://2
return SQL_C_CHAR;// CHAR, VARCHAR, DECIMAL, NUMERIC
case SQL_TYPE_TIMESTAMP:return SQL_C_TIMESTAMP;
case SQL_TIME:return SQL_C_TIME;
case SQL_DATE:return SQL_C_DATE;
case SQL_GUID:return SQL_C_GUID;
default:return SQL_UNKNOWN_TYPE;
}
return 0;
}