Re: Jaw drop: JDBC will let you update rows with the wrong data type (within reason)

I think it is the auto-cast in Db2 that kicks in. And why statement 3
fails. For that it can not cast the current object value.


ons. 6. okt. 2021 kl. 21.58 skrev David Gibbs via JAVA400-L <
[email protected]>:

> Folks:
>
> I just encountered a situation where JDBC allowed me to update rows in a
> table where the values did not match the column definition.
>
> As long as you use the setObject method, you can set a numeric column to
> a string value and a character column with a numeric value.
>
> The value contents have to match the column definition, but it doesn't
> seem to care what the data type being passed in.
>
> For instance:
>
> You create a table as such ...
>
> create table testtab1 (
>    decfield decimal(8,0),
>    charfield char(10)
> )
>
> ... and then run code like this ...
>
> try (
>    Connection conn = DriverManager.getConnection(url, props);
>    PreparedStatement stmt = conn.prepareStatement("insert into
> dxglib/testtab1 (decfield,charfield) values(?,?)");
> ) {
>
>    stmt.setObject(1, 1);
>    stmt.setObject(2, "xyz");
>    stmt.executeUpdate();
>
>    stmt.setObject(1, "2");
>    stmt.setObject(2, 3);
>    stmt.executeUpdate();
>
>    stmt.setObject(1, "A");
>    stmt.setObject(2, 3);
>    stmt.executeUpdate();
>
> } catch (Exception e) {
>    e.printStackTrace();
> }
>
> .. the first two updates will work fine, but the 3rd will fail.
>
> david
> --
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