In this recipe, we will show how you can add mappings for database functions, which are not available by default.
- Create a new class library project named
CustomDialectExample. - Install the
NHibernateandlog4netpackages using the NuGet Package Manager Console by executing the following command:Install-Package NHibernate Install-Package log4net
- Create a new class named
CustomMsSql2012Dialectusing the following code:public class CustomMsSq2012Dialect: MsSql2012Dialect { public CustomMsSq2012Dialect() { RegisterFunction("AddDays", new SQLFunctionTemplate( NHibernateUtil.DateTime, "dateadd(day,?2,?1)")); RegisterFunction("AddHours", new SQLFunctionTemplate( NHibernateUtil.DateTime, "dateadd(hour,?2,?1)")); RegisterFunction("AddMinutes", new SQLFunctionTemplate( NHibernateUtil.DateTime, "dateadd(minute,?2,?1)")); RegisterFunction("AddSeconds", new SQLFunctionTemplate( NHibernateUtil.DateTime, "dateadd(second,?2,?1)")); RegisterFunction("AddMilliseconds", new SQLFunctionTemplate( NHibernateUtil.DateTime, "dateadd(millisecond,?2,?1)")); } } - Use this dialect in your configuration, as described in Chapter 1, The Configuration and Schema.
The dialect has the RegisterFunction method, but it is not public, as all dialects are tightly coupled to the RDBMS they represent. Thus, to register a custom function we create a custom dialect class.
We use the SQLFunctionTemplate class to register four of our custom functions. This class implements the ISQLFunction interface. This interface is responsible for rendering the function into SQL.
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.