EJB-QL

[bhargavi kakarala]

hi all,

can somone explain about prameteres usage in EJB-QL
eg: in SELECT DISTINCT OBJECT(o) FROM Order o,IN(o.lineItems)l WHERE l.product.name=?1.how this is called.

[Magnus Stattin]

It would be called from a finder method defined in the home interface like this for example:
public Order findByProductName(String name);
Hope I understood your question
/Magnus

[Keith Rosenfield]

Hi bhargavi,
The way parameters work is EJB-Ql is as follows. In a query you use ?# as a placeholder for parameters. When the query is evaluated each ?# will be replaced by a parameter from the associated method. The number following the ? determines which parameter will replace it. For example ?2 will be replaced by the second parameter. The number of ?#s can not exceed the number of method parameters but can be less.
Let's assume your query
SELECT DISTINCT OBJECT(o) FROM Order o,IN(o.lineItems)l WHERE l.product.name=?1

is associated with the finder method
public Product findByProductName(String name);
?1 would be replaced by the first parameter which is name.

Hope this helps.

[bhargavi kakarala]

Thanks Keith & Magnus
I got it