Thank you for your answer.

Now, I'm preparing this sort of query directly appending the constant
value to the sql string. So it looks like:

int const;

String str = "SELECT FIELD1, " + const + " AS CONST, FIELD2 ";
str += "FROM TABLE1 ";
str += "WHERE FIELD1 = ?";

pst = conn.prepareStatement(str);
pst.setInt(1, val);
pst.execute();

Am I loosing the prepared statement's befenefits in this situation? The
const value will change in every new query.

The same question arises related to the "SELECT FIRST x SKIP y" clause.
In my application I use the same way, appending to the query string the
desired constant values, to make that kind of queries.

Thank you very much.

Juan Pedro

> > Now I want to use it from jaybird, by means of a prepared statement,
> > because the constant value will change in every new query.
> >
> > I tested it just replacing the constant value with the usual ? character
> > without success. It seem this parameter is not considered when preparing
> > the query so it fails because of some type mismatch in the subsequent
> > parameters.
>
> In fact you should get
>
> org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544569. Dynamic SQL
> Error
> SQL error code = -804
> Data type unknown
>
> This means that server does not know the type of the parameter to prepare
> it. This is the same issue as in SELECT * FROM myTable WHERE ? IS NULL OR
> myPk = ? that was discussed some time ago.
>
> > Isn't this kind of parametrized query currently supported?
>
> No, unfortunately this syntax is not supported. But if your query does not
> change itself, you can create a selectable procedure that will do the same
> thing.
>
> For example, if you had
>
> SELECT mainCol, ? AS selectParam FROM myTable WHERE someOtherCol = ?
>
> you should create following procedure
>
> CREATE PROCEDURE workaroundProc(
> firstParam INTEGER,
> secondParam VARCHAR
> ) RETURNS (
> mainCol TIMESTAMP,
> selectParam INTEGER
> ) AS BEGIN
> FOR SELECT myCol, :firstParam FROM myTable
> WHERE someOtherCol = :secondParam
> INTO :mainCol, :selectParam
> DO
> SUSPEND;
> END
>
> Then you can use
>
> SELECT mainCol, selectParam FROM workaroundProc(?, ?)
>
> This will give you the same result with virtually no performance loss.
>
> Roman
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>