Databases
StackOverflow2013
Postsdbo
POnull values in NHibernate returning list
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POnull values in NHibernate returning list
    primarykey
    data
    text
    <p>I'm trying to understand the following behaviour of NHibernate and can't.</p> <pre><code>session.CreateCriteria&lt;Param&gt;() .Add(Restrictions.Eq("GroupId", groupId)) .Add(Restrictions.Eq("ParamId", paramId)) .List&lt;Param&gt;() </code></pre> <p>This construction should return collection with 1 database row(object). But returns list with single null element. Could you suggest why?</p> <p>P.S. Param class mapping has a composite key.</p> <pre><code>public class Param { public Param() { } public Param(string groupId, string paramId, string paramName) : this() { GroupId = groupId; ParamId = paramId; ParamName = paramName; } public virtual string GroupId { get; protected set; } public virtual string ParamId { get; protected set; } public virtual string ParamName { get; protected set; } public virtual string Value { get; set; } public override bool Equals(object obj){...} public override int GetHashCode(){...} } public class ParamMap : ClassMap&lt;Param&gt; { public ParamMap() { Table("Params"); CompositeId() .KeyProperty(x =&gt; x.GroupId) .KeyProperty(x =&gt; x.ParamId) .KeyProperty(x =&gt; x.ParamName, "ParamName"); Map(x =&gt; x.Value, "ParamValue"); } } </code></pre> <p>This query is copied from database log. NHibernate executes it.</p> <pre><code>SELECT THIS_.GROUPID AS GROUPID19_0_, THIS_.PARAMID AS PARAMID19_0_, THIS_.PARAMNAME AS PARAMNAME19_0_, THIS_.PARAMVALUE AS PARAMVALUE19_0_ FROM PARAMS THIS_ WHERE THIS_.GROUPID = :1 AND THIS_.PARAMID = :2 \ WorkHour,TotalHours, / </code></pre> <p>Returns 1 row:</p> <pre><code>GroupId = "WorkHour" ParamId = "TotalHours" ParamName = (empty) ParamValue = YES </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAdelf
    1. USAdelf
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COCould you tell us more about the Param class and the values in the DB?
      singulars
      1. POnull values in NHibernate returning list
      1. USJTMon
    2. COI updated the question.
      singulars
      1. POnull values in NHibernate returning list
      1. USAdelf
    3. COtried without the _protected_ modifier on the key properties ? Also, do your Equals and GetHashCode handle the null value of paramName correctly ?
      singulars
      1. POnull values in NHibernate returning list
      1. USjbl
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload