web server - Borland Technical Publications

Overriding SQL generated from EJB-QL by the CMP engine
The ejbSelects for dynamic queries are:
public java.util.Collection selectDynamicLocal(java.lang.String ejbql,
Class[] types, Object[] params)
throws javax.ejb.FinderException
public java.util.Collection selectDynamicLocal(java.lang.String ejbql, Class[]
types, Object[] params, java.lang.String sql)
throws javax.ejb.FinderException
public java.util.Collection selectDynamicRemote(java.lang.String ejbql,
Class[] types, Object[] params)
throws javax.ejb.FinderException
public java.util.Collection selectDynamicRemote(java.lang.String ejbql, Class[]
types, Object[] params, java.lang.String sql)
throws javax.ejb.FinderException
public java.sql.ResultSet selectDynamicResultSet(java.lang.String ejbql,
Class[] types, Object[] params)
throws javax.ejb.FinderException
Note
public java.sql.ResultSet selectDynamicResultSet(java.lang.String ejbql,
Class[] types, Object[] params, java.lang.String sql)
throws javax.ejb.FinderException
where the following applies:
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■
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java.lang.String ejbql: this represents the actual EJB-QL syntax.
Class[] types: this array gives the class types of the parameters to the select or
finder method (it can be an empty array if there are no parameters).
Object[] params: this array gives the actual values of the parameters. This is the
same as the parameters argument of the regular select or finder method.
The return type of a dynamic select or finder is always java.util.Collection, with
the exception of the selectDynamicResultSet. If there is a single instance of the object
or value type returned from the query, it is the first member of the collection.
Dynamic queries follow the same rules as regular queries.
java.lang.String sql: User specified sql. If specified, this will override the sql
generated by EJB-QL.
There should not be any trace of the eight methods associated with dynamic queries in
your deployment descriptor.
Overriding SQL generated from EJB-QL by the CMP engine
Important
Note
This feature is for advanced users only!
The Borland CMP engine generates SQL calls to your database based on the EJB-QL
you enter in your deployment descriptors. Depending on your database
implementation, the generated SQL may be less than optimal. You can capture the
generated SQL using tools supplied by your backing-store implementation or another
development tool. If the generated SQL is not optimal, you can replace it with your
own. However, we offer no validation on the user SQL.
A problem with your SQL may generate an exception which can potentially crash the
system.
158 BES Developer’s Guide