/*      execute(arg,...)     */
static VALUE stmt_execute(int argc, VALUE *argv, VALUE obj)
{
    struct mysql_stmt *s = DATA_PTR(obj);
    MYSQL_STMT *stmt = s->stmt;
    my_bool true = 1;
    my_bool false = 0;
    int i;

    check_stmt_closed(obj);
    if (s->param.n != argc)
        rb_raise(eMysql, "execute: param_count(%d) != number of argument(%d)", s->param.n, argc);
    memset(s->param.bind, 0, sizeof(*(s->param.bind))*argc);
    for (i = 0; i < argc; i++) {
        switch (TYPE(argv[i])) {
        case T_NIL:
            s->param.bind[i].buffer_type = MYSQL_TYPE_NULL;
            s->param.bind[i].is_null = &true;
            break;
        case T_FIXNUM:
            s->param.bind[i].buffer_type = MYSQL_TYPE_LONG;
            s->param.bind[i].buffer = &(s->param.buffer[i]);
            *(long*)(s->param.bind[i].buffer) = FIX2INT(argv[i]);
            break;
        case T_BIGNUM:
            s->param.bind[i].buffer_type = MYSQL_TYPE_LONGLONG;
            s->param.bind[i].buffer = &(s->param.buffer[i]);
            *(long long*)(s->param.bind[i].buffer) = rb_big2ll(argv[i]);
            break;
        case T_FLOAT:
            s->param.bind[i].buffer_type = MYSQL_TYPE_DOUBLE;
            s->param.bind[i].buffer = &(s->param.buffer[i]);
            *(double*)(s->param.bind[i].buffer) = NUM2DBL(argv[i]);
            break;
        case T_STRING:
            s->param.bind[i].buffer_type = MYSQL_TYPE_STRING;
            s->param.bind[i].buffer = RSTRING(argv[i])->ptr;
            s->param.bind[i].buffer_length = RSTRING(argv[i])->len;
            s->param.length[i] = RSTRING(argv[i])->len;
            s->param.bind[i].length = &(s->param.length[i]);
            break;
        default:
            if (CLASS_OF(argv[i]) == rb_cTime) {
                MYSQL_TIME t;
                VALUE a = rb_funcall(argv[i], rb_intern("to_a"), 0);
                s->param.bind[i].buffer_type = MYSQL_TYPE_DATETIME;
                s->param.bind[i].buffer = &(s->param.buffer[i]);
                t.second_part = 0;
                t.neg = 0;
                t.second = FIX2INT(RARRAY(a)->ptr[0]);
                t.minute = FIX2INT(RARRAY(a)->ptr[1]);
                t.hour = FIX2INT(RARRAY(a)->ptr[2]);
                t.day = FIX2INT(RARRAY(a)->ptr[3]);
                t.month = FIX2INT(RARRAY(a)->ptr[4]);
                t.year = FIX2INT(RARRAY(a)->ptr[5]);
                t.time_type = MYSQL_TYPE_DATETIME;
                *(MYSQL_TIME*)&(s->param.buffer[i]) = t;
            } else if (CLASS_OF(argv[i]) == cMysqlTime) {
                MYSQL_TIME t;
                s->param.bind[i].buffer_type = MYSQL_TYPE_DATETIME;
                s->param.bind[i].buffer = &(s->param.buffer[i]);
                t.second_part = 0;
                t.neg = 0;
                t.second = NUM2INT(rb_iv_get(argv[i], "second"));
                t.minute = NUM2INT(rb_iv_get(argv[i], "minute"));
                t.hour = NUM2INT(rb_iv_get(argv[i], "hour"));
                t.day = NUM2INT(rb_iv_get(argv[i], "day"));
                t.month = NUM2INT(rb_iv_get(argv[i], "month"));
                t.year = NUM2INT(rb_iv_get(argv[i], "year"));
                t.time_type = MYSQL_TYPE_DATETIME;
                *(MYSQL_TIME*)&(s->param.buffer[i]) = t;
            } else
                rb_raise(rb_eTypeError, "unsupported type: %d", TYPE(argv[i]));
        }
    }
    if (mysql_stmt_bind_param(stmt, s->param.bind))
        mysql_stmt_raise(stmt);

    if (mysql_stmt_execute(stmt))
        mysql_stmt_raise(stmt);
    if (s->res) {
        MYSQL_FIELD *field;
        if (mysql_stmt_store_result(stmt))
            mysql_stmt_raise(stmt);
        field = mysql_fetch_fields(s->res);
        for (i = 0; i < s->result.n; i++) {
            if (s->result.bind[i].buffer_type == MYSQL_TYPE_STRING ||
                s->result.bind[i].buffer_type == MYSQL_TYPE_BLOB) {
                s->result.bind[i].buffer = xmalloc(field[i].max_length);
                memset(s->result.bind[i].buffer, 0, field[i].max_length);
                s->result.bind[i].buffer_length = field[i].max_length;
            } else {
                s->result.bind[i].buffer = xmalloc(sizeof(MYSQL_TIME));
                s->result.bind[i].buffer_length = sizeof(MYSQL_TIME);
                memset(s->result.bind[i].buffer, 0, sizeof(MYSQL_TIME));
            }
        }
        if (mysql_stmt_bind_result(s->stmt, s->result.bind))
            mysql_stmt_raise(s->stmt);
    }
    return obj;
}