Embedded Firebird 1.5.3
jaybird 2.0.1

I have a table:
CREATE TABLE ORDERED (
ORDER_ID BIGINT NOT NULL,
.... some basic fields ...
);

and a constraint:
ALTER TABLE ORDERED ADD PRIMARY KEY (ORDER_ID);
this is the integ_85 contstraint referred to below

I try to update the following lines in non-autocommit mode:
st.executeUpdate("ALTER TABLE ORDERED ADD ADDITIONAL_PRICE BIGINT
DEFAULT 0 NOT NULL");
st.executeUpdate("UPDATE ORDERED SET ADDITIONAL_PRICE = 0");

And I get the following error:

org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544665.
violation of PRIMARY or UNIQUE KEY constraint "INTEG_85" on table
"ORDERED"
at
org.firebirdsql.jdbc.AbstractStatement.executeUpdate(AbstractStatement.java:250)
at woodpecker.apizzas.UpdateStuff.updateDB(UpdateStuff.java:221)
at woodpecker.apizzas.Main.main(Main.java:162)
at org.firebirdsql.gds.GDSException: violation of PRIMARY or UNIQUE
KEY constraint "INTEG_85" on table "ORDERED"
at
org.firebirdsql.gds.impl.jni.JniGDSImpl.native_isc_dsql_execute2(Native
Method)
at
org.firebirdsql.gds.impl.jni.BaseGDSImpl.iscDsqlExecute2(BaseGDSImpl.java:374)
at
org.firebirdsql.gds.impl.GDSHelper.executeStatement(GDSHelper.java:222)
at
org.firebirdsql.jdbc.AbstractStatement.internalExecute(AbstractStatement.java:1087)
at
org.firebirdsql.jdbc.AbstractStatement.executeUpdate(AbstractStatement.java:246)
at woodpecker.apizzas.UpdateStuff.updateDB(UpdateStuff.java:221)
....

Is this normal?

Thanks,
John