NHibernate SysCache2 - dependency breaks cache

问题

Company class:

class Company {
  public virtual int Id { get;set;}
  public virtual string Name { get;set;}
  public virtual int IntProp { get;set;}
}

Companies table:

CREATE TABLE Companies (
  Id INT PRIMARY KEY,
  Name NVARCHAR(50) NOT NULL,
  IntProp INT NULL );

Here is my web.config:

<syscache2>
    <cacheRegion name="RefData"></cacheRegion>
    <cacheRegion name="Company">
        <dependencies>
            <commands>
                <add name="CompanyCommand"
                         command="SELECT * FROM Companies WHERE Deleted = 0"
        />
            </commands>
        </dependencies>
    </cacheRegion>
</syscache2>

Problem: other entities in the RefData cache region (which never change, think countries, etc.) are cached fine. Company, on the other hand, is not.

回答1:

The solution consisted of solving multiple problems:

IntProp was nullable on the table, and property was not nullable int. This led to NHibernate not being able to set NULLs when getting a row, so the property value became 0. When session flushed, it saw a modification (NULL to 0) and threw exceptions about modifying readonly data. (This is a NH design flaw, IMO)
The dependency query SELECTs all columns (*), which is not supported by the dependency mechanism. Instead, each column has to be listed. (This fails quietly, which again is a SQL design flaw, IMO)
The dependency query FROM clause has table name but omits the schema name, which is also not supported. Adding dbo. fixed it. I spent 4 hours to find this. (Again, quiet failure, SQL flaw)
After going to production lane, user permission bugs appeared. Those can be fixed by following http://social.technet.microsoft.com/Forums/exchange/en-US/99321f54-1fef-4860-9fe9-5966a46fe582/once-for-all-right-permissions-for-sqldependency-please

Hope this helps someone.

PS. Per request, final result:

class Company {
  public virtual int Id { get;set;}
  public virtual string Name { get;set;}
  public virtual int? IntProp { get;set;}
}

<syscache2>
    <cacheRegion name="RefData"></cacheRegion>
    <cacheRegion name="Company">
        <dependencies>
            <commands>
                <add name="CompanyCommand"
                         command="SELECT Id, Name, IntProp FROM dbo.Companies WHERE Deleted = 0"
        />
            </commands>
        </dependencies>
    </cacheRegion>
</syscache2>

来源：https://stackoverflow.com/questions/23656803/nhibernate-syscache2-dependency-breaks-cache

标签

sql

nhibernate

sqldependency

syscache2