Date: Thu, 08 Sep 2011 09:48:36 +0200
From: Lele <lele@lele.com>
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Subject: Re: CriteriaQuery and JPA
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Il 07/09/2011 20:02, Lew ha scritto:

> Read the Javadocs for 'Root#get(String attributeName)'.  You gave a 'null' attribute name, and what you tried to do wasn't giving an attribute *name*, but an attribute *value*.

Ok, I try to remake my question.
My class has a field named 'username':

public MyClass{
     public String username;
}

I have to create a where clause that check if this field is equal to a 
constant value:
WHERE username = "test"

I understand that Root#get(String attributeName) give to me the 
attribute name (and not the attribute value), so how can i put a 
constant value inside the clause?

filter.where(criteriaBuilder.equal(from.get("username"),"test"));

with this code i would expect a where clause like the above. Instead i 
have the null value : WHERE username = ?

Sorry but I'm new to JPA