!SQLException:sql.bind:42000!Column type mismatch

9 Sep 2019

      Hi,

I'm doing some tests about bind operation with v11.33.11 (Apr2019-SP1)
and here's how to reproduce:

```
mclient -d test
sql>create table unary(a int);
sql>insert into unary(a) select value from generate_series(1, 101, 1);

mclient -d test -l mal
mal>sql.init();
mal>s := sql.mvc();
mal>a := sql.bind(s, "sys", "unary", "a", 0);
```
Then I got `!SQLException:sql.bind:42000!Column type mismatch`.

I traced it down to `sql/backends/monet5/sql.c:mvc_bind_wrap`, `int
coltype = getBatType(getArgType(mb, pci, 0));` coltype is set to 255
here, which confused me about what this coltype is used for.

Also in `sql/backends/monet5/sql.mal`, the comment says the access
kind (last argument) is divided into `0, base table`, `1, inserts` and
`2, updates`. In what scenarios are these values used? Is `0` for read
only operations? What about delete operations?

Thanks for your help.

Best regards,
Jiading Guo