Frequently Asked Questions
You'll need to install CodeSmith, and you can get a free eval copy from the CodeSmith website. Once you've done that go to the Getting Started section of this wiki for step by step instructions.
It can be done! .netTiers generates C#, but the assemblies are CLS-compliant. This means that you can build a system from any combination of .NET languages and things generally work the way you expect. There are some VB Gotchas though, so make sure you read up before you consider mixing VB.NET with .netTiers.
One company was kind enough to compare multiple different data access layers. In all their tests, netTiers proved to be the fastest, in most cases by a reasonable margin. .netTiers achieves this speed through simplicity. While there is C# wrapped around the functions to give additional features, the actual data exchange with the database server is handled primarily through stored procedures with very simple queries. Complicated joins and where clauses often generated by other data access layers are not part of the core functionality of netTiers .
.netTiers is a tool ideally suited for developers that have a good idea about database schema design and C# development patterns and practices. It also helps if the developer knows a bit about Code Smith since that is the tool used to generate the .NetTiers. Because .netTiers is not a commercial tool there are some rough edges, these are being worked on to constantly improve the development process as such, it would be helpful to have a strong senior architect \ developer on the team to keep the structure secure while working out any kinks.
If CodeSmith isn't recognizing the changes in your database schema, try clicking the [...] button of the SourceTables or SourceDatabase properties from your property set. Alternatively, you can close and re-open CodeSmith. UPDATE: In CodeSmith 4.1+, there is a refresh schema button on the property grid toolbar.
When a table changes in SQL Server specifically, it does not always update the meta data for the view. .netTiers uses the views meta data when generating the object representing the view. The fix is to open up the view, and re-execute it, then .netTiers should pick up correct information.
It is possible to deep load an object graph that represents a set of related tables. The API contains several deep-load options that offer control over recursion, parent/child inclusion, exactly which entity types (tables) should be included.
Deep-load works the best when loading related data that has a tree-like structure. Deep-load will attempt to handle recursive or circular relationships, but depending on the circumstances, these structures may limit the effectiveness of deep-load.
I set the NetTiersProvider.DefaultCommandTimeout property, so why does my (slow) Sproc time out using the SQL provider?
Contrary to what you might think, the family of Execute* functions in Data.Bases.NetTiersProvider.ProviderBase as implemented by SqlNetTiersProvider, does not honor/implement the DefaultCommandTimeout found in NetTiersProvider as the CommandTimeout value for command execution.
Barring a change to the templates, a possible workaround is the following code:
// adjust command timeout if the provider is a SQL database
Data.SqlClient.SqlNetTiersProvider p = DataRepository.Provider as Data.SqlClient.SqlNetTiersProvider;
if (null == p) {
// provider is not a SQL provider, do something else appropriate
DataRepository.Provider.ExecuteNonQuery("sp_MySlowSproc");
} else {
// get the SqlDatabase Microsoft.Practices.EnterpriseLibrary.Data.Sql.SqlDatabase db = new SqlDatabase(p.ConnectionString);
// create a command for the slow sproc
System.Data.Common.DbCommand cmd = db.GetStoredProcCommand("sp_MySlowSproc");
// set the timeout as set on the provider (or as needed)
cmd.CommandTimeout = DataRepository.Provider.DefaultCommandTimeout;
// execute the command (any of the Execute* family)
DataRepository.Provider.ExecuteNonQuery(cmd);
}Another possibility would be to make use of the method:
Data.SqlClient.StoredProcedureProvider.GetCommandWrapper()but it would only replace approximately 2 of the lines above, and considering the useStoredProcedure parameter it doesn't seem that appropriate.
Issue: GetTotalItems() method on an EntityProvider object uses the same SQL as the Get() methods, which results in an entire record set being retrieved when all that is needed is to get a Count of the items in the database table.
Workaround: Call the GetPaged()method directly, but only specify a pageLength of 1. The out parameter of the method will contain the correct count. Example: (Using AdventureWorks DB)
int retVal;
TList<Product> prod = DataRepository.ProductProvider.GetPaged(0,1, out retVal);
return retVal;This still returns a single entity item (if any exist), but this is at least more efficient than returning an entire table's data to simply get a count.
Issue: start parameter indicates "Row number at which to start reading". In fact, the start parameter indicates what page to retrieve. Supplying a row number to this parameter will return an incorrect page.
Workaround: Before passing a value to this parameter, it is advisable to divide the desired row number by the desired page size. This will return the correct result set containing the value required.
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Why don't some data access methods (such as Find) show up when I attempt to bind a data source to a service object?
There is no meta data telling the framework to display the function.
Place the following code above the method declaration:
[DataObjectMethod(DataObjectMethodType.Select)]
public virtual TList<YourObject> Find(string whereClause)Recompile and you should now see that method available.
The NetTiers Web Library is a set of Controls and Objects that provide powerful tools to make your web development projects with NetTiers much easier and more efficient. The Web Library offers both Strongly Typed DataSource Controls as well as the more generic EntityDataSource. These are inherited from the ObjectDataSource, but have been improved to exploit the functionality of the NetTiers framework. You can find more info in the Web Layer section of this wiki.
The WinForms library is similar to the NetTiers Web Controls library, but is still in a developmental stage. It will be a suite of Controls and Objects that will make your WinForms development easier and more efficient.
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