Re: BUG #5099: When MetaData is acquired, it becomes an SQL error.

On Wed, 7 Oct 2009, konishi wrote:

> Bug reference:      5099
> PostgreSQL version: 8.4.1
> Description:        When MetaData is acquired, it becomes an SQL error.
> Details:
>
> In sample source and sample db
> when used postgresql-8.4-701.jdbc3.jar is error
> when used postgresql-8.3-603.jdbc3.jar is no error
>
>
> The error disappears when "prepared.getParameterMetaData()" row delete.
>
> String url = "jdbc:postgresql://XXX.XXX.XXX.XXX:5432/test";
> Connection con = DriverManager.getConnection(url, "postgres", "test");
> try{
>    String sql = "insert into test(filename,upddate) values(?,?)";
>    PreparedStatement prepared = con.prepareStatement(sql);
>    System.out.println("ParameterMetaData[" +
> prepared.getParameterMetaData() + "]");
>    prepared.setString(1, "0");
>    prepared.setTimestamp(2, new
> Timestamp(Calendar.getInstance().getTimeInMillis()));
>    prepared.executeUpdate();
> }catch(Exception e){
>    System.out.println(e.getMessage());
> }
>
> error message:
> java.lang.IllegalArgumentException: Can't change resolved type for param: 1
> from 1043 to 25
>     at
> org.postgresql.core.v3.SimpleParameterList.setResolvedType(SimpleParameterLi
> st.java:230)
>     at


I have applied a fix to CVS for this problem and it will be included in
the next release.

For the 8.4 release an optimization was added to avoid re-describing a
statement if we already had the type information available by copying the
resolved type information from the query to the provided parameters.  Its
goal was just to overwrite parameters without a type (unknown), but it was
actually overwriting all types which could change the query's desired
behavior.  In this case a safeguard to prevent that change was throwing
the exception noted.

Kris Jurka