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jfblier
 Post subject: Unable to retreive the key for a object
PostPosted: Thu Oct 16, 2003 8:49 am 
Newbie

Joined: Wed Oct 15, 2003 9:20 am
Posts: 12
Location: Qu
I am able to create a new object in the DB but when I try to retreive it, I receive a null string for my key. I have a other string field(that is not a key) and the retreived value is good.

Here is my hbm file:
Code:
<hibernate-mapping>
  <class name="dti.xmscore.model.cLaboratory" table="lab">
    <id name="aNewLabID" column="lab_id" type="string" length="20">
      <generator class="assigned"/>
    </id>

    <property name="aManagerName" column="manager_name" type="string" length="30"/>
   
  </class>
</hibernate-mapping>


Here is my code to retreive the object:
Code:
try {
   List results = (List) session.find(key);
   cLaboratory lab = (cLaboratory)results.get(0);
   System.out.pritnln(lab);
} catch (Exception e) {
   ...
}


The output is:
Code:
   dti.xmscore.model.cLaboratory@6f9b8e[aNewLabID=<null>]


If I change my key to a long with hilo generation it work well:
Code:
<hibernate-mapping>
  <class name="dti.xmscore.model.cLaboratory" table="lab">
    <id name="id" column="key_id" type="long" unsaved-value="null">
      <generator class="hilo"/>
    </id>

    <property name="aManagerName" column="manager_name" type="string" length="30"/>
   
  </class>
</hibernate-mapping>


The output is now:
Code:
dti.xmscore.model.cLaboratory@14db0e3[id=1]


Any idea?

Thanks.
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emmanuel
 Post subject:
PostPosted: Thu Oct 16, 2003 9:34 am 
Hibernate Team
Hibernate Team

Joined: Sun Sep 14, 2003 3:54 am
Posts: 7256
Location: Paris, France
Can you show us your creation code ?
Is there null in DB ?
Did you explicitly call cLaboratory.setaNewLabID(myNotNullKey) before saving it ?
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jfblier
 Post subject:
PostPosted: Thu Oct 16, 2003 9:54 am 
Newbie

Joined: Wed Oct 15, 2003 9:20 am
Posts: 12
Location: Qu
Thanks.

The code to create the object is ok, because the lab_id field in the database contains 'lab200000240' that is the laboratory identifier. There's no null in the DB.

Here's the creation code:
Code:
cLaboratory lab = new cLaboratory("lab200000240", "MyName");
session.save(lab);
session.flush();
session.connection().commit();


It's strange, because when a retreive the object stored, It display 'MyName' string.


epbernard wrote:
Can you show us your creation code ?
Is there null in DB ?
Did you explicitly call cLaboratory.setaNewLabID(myNotNullKey) before saving it ?
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emmanuel
 Post subject:
PostPosted: Thu Oct 16, 2003 10:15 am 
Hibernate Team
Hibernate Team

Joined: Sun Sep 14, 2003 3:54 am
Posts: 7256
Location: Paris, France
Can I have a look at cLaboratory class code ?
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jfblier
 Post subject:
PostPosted: Thu Oct 16, 2003 10:27 am 
Newbie

Joined: Wed Oct 15, 2003 9:20 am
Posts: 12
Location: Qu
Here's the class definition:

public final class cLaboratory implements Serializable {

/** The unique laboratory ID */
protected String aNewLabID;

/** The name of the owner/manager of this lab. */
protected String aManagerName;

/** default constructor */
protected cLaboratory() {
}

/**
* Minimal constructor
*/
public cLaboratory(String aNewLabID) {
super();
aLabID = 0;
this.aNewLabID = aNewLabID;
mInit();
}

private String getaNewLabID() {
return this.aNewLabID;
}

private void setaNewLabID(String newLabID) {
this.aNewLabID = aNewLabID;
}

private String getaManagerName() {
return this.aManagerName;
}

private void setaManagerName(String aManagerName) {
this.aManagerName = aManagerName;
}

public String toString() {
return new ToStringBuilder(this)
.append("aNewLabID", getaNewLabID())
.toString();
}

public boolean equals(Object other) {
if ( !(other instanceof cLaboratory) ) return false;
cLaboratory castOther = (cLaboratory) other;
return new EqualsBuilder()
.append(this.getaNewLabID(), castOther.getaNewLabID())
.isEquals();
}

public int hashCode() {
return new HashCodeBuilder()
.append(getaNewLabID())
.toHashCode();
}
}


epbernard wrote:
Can I have a look at cLaboratory class code ?
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emmanuel
 Post subject:
PostPosted: Thu Oct 16, 2003 10:51 am 
Hibernate Team
Hibernate Team

Joined: Sun Sep 14, 2003 3:54 am
Posts: 7256
Location: Paris, France
Hum, that's not the class you used.
There is not Constructor(String, String)
mInit() isn't defined
aLabID=0 has no declaration.

The error is probably in
Code:
private void setaNewLabID(String newLabID) {
   this.aNewLabID = aNewLabID;
}


replace by this.aNewLabID = newLabID. aNewLabID = this.aNewLabID

Hibernate use setaNewLabId which is broken.

Hint, use the _newLabId conevntion for internal attribute, this will prevent such mistake.
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jfblier
 Post subject:
PostPosted: Thu Oct 16, 2003 11:01 am 
Newbie

Joined: Wed Oct 15, 2003 9:20 am
Posts: 12
Location: Qu
Oups, excuse-me, I have put my test class trying to resolve my problem. Sorry.

Here is my real class:
Code:
package dti.xmscore.model;

import java.io.Serializable;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;

public final class cLaboratory implements Serializable {

    /** The unique laboratory ID */
    protected String        aNewLabID;
   
    /** The name of the owner/manager of this lab. */
    protected String        aManagerName;

    /** default constructor */
    protected cLaboratory() {
    }
   
    /**
     * Minimal constructor
     */
    public cLaboratory(String aNewLabID) {
        this.aNewLabID = aNewLabID;
    }

    public String getaNewLabID() {
        return this.aNewLabID;
    }

    public void setaNewLabID(String newLabID) {
        this.aNewLabID = aNewLabID;
    }

    public String getaManagerName() {
        return this.aManagerName;
    }

    public void setaManagerName(String aManagerName) {
        this.aManagerName = aManagerName;
    }
   
    public String toString() {
        return new ToStringBuilder(this)
            .append("aNewLabID", getaNewLabID())
            .toString();
    }

    public boolean equals(Object other) {
        if ( !(other instanceof cLaboratory) ) return false;
        cLaboratory castOther = (cLaboratory) other;
        return new EqualsBuilder()
            .append(this.getaNewLabID(), castOther.getaNewLabID())
            .isEquals();
    }

    public int hashCode() {
        return new HashCodeBuilder()
            .append(getaNewLabID())
            .toHashCode();
    }
}



Thanks for your help. The setaNewLabId was broken. A stupid cut/paste when I was trying to make fonctionnal my class.

I have a other question for you: I have a Vector of Strings in a Class and I want to persist this list in the DB. I don't want to create a class only for one field. What is the best way to do it?

Thanks.


epbernard wrote:
Hum, that's not the class you used.
There is not Constructor(String, String)
mInit() isn't defined
aLabID=0 has no declaration.

The error is probably in
Code:
private void setaNewLabID(String newLabID) {
   this.aNewLabID = aNewLabID;
}


replace by this.aNewLabID = newLabID. aNewLabID = this.aNewLabID

Hibernate use setaNewLabId which is broken.

Hint, use the _newLabId conevntion for internal attribute, this will prevent such mistake.
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emmanuel
 Post subject:
PostPosted: Thu Oct 16, 2003 11:07 am 
Hibernate Team
Hibernate Team

Joined: Sun Sep 14, 2003 3:54 am
Posts: 7256
Location: Paris, France
Use a collection of values. Have a look at Hibernate reference guide section 5.3.
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steve
 Post subject:
PostPosted: Thu Oct 16, 2003 11:21 am 
Hibernate Team
Hibernate Team

Joined: Tue Aug 26, 2003 3:00 pm
Posts: 1816
Location: Austin, TX
So are you still having problems with this? If so, I don't understand:
Quote:
but when I try to retreive it, I receive a null string for my key


and

Quote:
It's strange, because when a retreive the object stored, It display 'MyName' string


seem contradictory.


Quote:
Use a collection of values.

Depends how these get stored. If they are on a seperate table keyed by the owning class id, then a collection of values will work. If they are on the same table, you can utilize a UserType or store the collection in its serialized format.
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jfblier
 Post subject:
PostPosted: Thu Oct 16, 2003 11:48 am 
Newbie

Joined: Wed Oct 15, 2003 9:20 am
Posts: 12
Location: Qu
Thanks.

epbernard wrote:
Use a collection of values. Have a look at Hibernate reference guide section 5.3.
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jfblier
 Post subject:
PostPosted: Thu Oct 16, 2003 11:50 am 
Newbie

Joined: Wed Oct 15, 2003 9:20 am
Posts: 12
Location: Qu
No. Now my problem is solve. That was the setter that was incorrectly coded.

Thanks.

steve wrote:
So are you still having problems with this? If so, I don't understand:
Quote:
but when I try to retreive it, I receive a null string for my key


and

Quote:
It's strange, because when a retreive the object stored, It display 'MyName' string


seem contradictory.


Quote:
Use a collection of values.

Depends how these get stored. If they are on a seperate table keyed by the owning class id, then a collection of values will work. If they are on the same table, you can utilize a UserType or store the collection in its serialized format.
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