Using Shared Projects in ASP.NET

Shared projects are used to facilitate cross platform development. This allows you to reference an entire project as opposed to just a single assembly.

Shared project is a shred bucket of code. At compile time, any project that reference the shared project will have all of the files (including folder structure) and then they will be compiled. You wouldn’t see any separate DLL as you might have seen in PCL (Portable class libraries).

A shared project is not going to be compiled on its own. The code in the shared project is incorporated into assembly that reference it and compiled within that assembly.

Let’s create a shared project;

Create a class Math with a static method Add.

namespace SharedProject1
{
    public class Math
    {
        public static int Add(int x, int y)
        {
#if NETCOREAPP1_1
            return (x + y) + 3;
#else
            return (x + y) + 13;
#endif
        }
    }
}

Add SharedProject reference to your project. If your project is targeting .NET Core 1.1, the relevant piece of code in #if/#endif will run.

//.NET Core 1.1
SharedProject1.Math.Add(3, 4);      //return 10

//.NET Core 1.0
SharedProject1.Math.Add(3, 4);      //return 20

Here is some recommendation of using Shared Projects and Portable Class Libraries;

How the code is reused

  1. Shared Projects: Source Code (All source code is available to your reference project)
  2. PCL: Reference is available at Assembly level (for example MyLibrary.dll)

Compile time behavior

  1. Shared Projects: All source code is copied into each referenced project and compiled there
  2. PCL: Nothing new. Its compiled as usuall.

Visual Studio support

  1. Shared Projects: Full Support
  2. PCL: Each plateform is compiled separately. This can be accomplished thru IOC.

#IFDEF Support

  1. Shared Projects: Full Support
  2. PCL: Unsupported

.NET Framework Support

  1. Shared Projects: Full Support
  2. PCL: Limited

The core problem with shared project is difficulty of code testing because of conditional compilation directives. This in turn introduce errors that you wouldn’t know until you have actually compiled your application.

Resources

https://dev.to/rionmonster/sharing-is-caring-using-shared-projects-in-aspnet-e17

https://stackoverflow.com/questions/30634753/what-is-the-difference-between-a-shared-project-and-a-class-library-in-visual-st

Using SSIS Script task with Object variable and ADO Data Set

My input is a Report Date. I would like to create a collection object of DateTime using Script task with this input. There is no Data Flow in this work flow. Later, I will be using this collection object in a Foreach loop container.

The object type of a package variable is really ADO dataset. This is finished package;

Fig: 1


Variables window

Fig: 2

Task A – SQLT – Report Date Lookup

Fig: 3
Fig: 4

Task B – SCPT – Build Pending Report Dates

Fig: 5
private static DataTable MakeDateDataTableFor(DateTime reportDate)
        {
            //create a new Data Table
            DataTable table = new DataTable();
            //Declare variables for DataColumn and DataRow objects
            DataRow row;
            DataColumn column;

            //Create a new DataColumn and set it's data type
            column = new DataColumn();
            column.DataType = System.Type.GetType("System.DateTime");
            column.ColumnName = "ReportDate";
            column.ReadOnly = true;
            table.Columns.Add(column);

            //Create three new DataRow objects and add them to the DataTable
            for (int i=0; i <=2; i++)
            {
                row = table.NewRow();
                row["ReportDate"] = reportDate.AddDays(i);
                table.Rows.Add(row);
            }
            return table;
        }

             /// <summary>
        /// This method is called when this script task executes in the control flow.
        /// Before returning from this method, set the value of Dts.TaskResult to indicate success or failure.
        /// To open Help, press F1.
        /// </summary>
             public void Main()
             {
            // TODO: Add your code here
            var reportDate = (DateTime)Dts.Variables["User::ReportDate"].Value;
            //Create ADO Data Table object
            DataTable table = MakeDateDataTableFor(reportDate);
            Dts.Variables["User::ReportDateCollection"].Value = table;

                    Dts.TaskResult = (int)ScriptResults.Success;
             }

Task C – FELoop – Data processing for each date

Fig: 6
Fig: 7

Task D – SCPT – Show pending dates

Fig: 8
public void Main()
             {
            // TODO: Add your code here
            MessageBox.Show(Dts.Variables["User::ReportStartDate"].Value.ToString());
                    Dts.TaskResult = (int)ScriptResults.Success;
             }

Resources

https://www.blogger.com/blog/post/edit/2414567817322296815/3075025082999390053

You can read more about Data Tables here;

https://docs.microsoft.com/en-us/dotnet/api/system.data.datatable?redirectedfrom=MSDN&view=net-5.0

Continue Foreach loop after task failure in SSIS

I would like to continue a Foreach loop container even if a task, for example, script task fails. Here is a quick fix;

Press F4, this will bring up Properties window. Change “ForceExecutionResult” property to “Success”.

Foreach loop will continue even if script task inside fails.

The recommended way to get a good error message from script task, decorate them with try/catch block. Here is an example;

try
{
   var x = 1/0;
}
catch (Exception ex)
            {
                var message = $"my error. ERR: {ex.Message.ToString()}";
                Dts.Events.FireError(1, ex.TargetSite.ToString(), message, "", 0);
                Dts.TaskResult = (int)ScriptResults.Failure;        
            }

These are good references on the topic;

https://www.mssqltips.com/sqlservertip/3575/continue-a-foreach-loop-after-an-error-in-a-sql-server-integration-services-package/

https://richardswinbank.net/ssis/errors_in_script_tasks_and_components

Cross Apply and Outer Apply

Microsoft has introduced APPLY operator in SQL Server 2005. It allows joining between two table expressions, for example joining left/outer table expression with right/inner table expression. The way it works is that we have a table-valued expression on the right side and we want this table-valued expression to be evaluated for each row from the left table expression.

An ideal use case would be where we are unable to form any kind a join between two tables. For example a project table and calendar table.

(Left Side Table – Project Table)

ProjectKey           ProjectEndDate

XX-ABC10            2018-10-31

XX-ABC11            2018-11-30

XX-ABD12            2019-01-31

XX-ABC13

(Right Side Table – Calendar Table)

FiscalQuarterStartDate   FiscalQuarterEndDate

2018-10-01                        2018-12-31

2019-01-01                        2019-03-31

Each ProjectEndDate falls between a FiscalQuarter. We need to append a new column in our result set that will be FiscalQuarterEndDate.

Here is the query;

SELECT p.ProjectKey, p.ProjectEndDate, dates.FiscalQuarterEndDate 
FROM Project p
CROSS APPLY
(
	SELECT FiscalQuarterEndDate 
	FROM FiscalCalendar calendar
	WHERE 1=1
	AND p.ProjectEndDate 
	BETWEEN calendar.FiscalQuarterStartDate AND calendar.FiscalQuarterEndDate
) dates
WHERE 1=1

Here is the result;

ProjectKey           ProjectEndDate                 FiscalQuarterEndDate

XX-ABC10            2018-10-31                        2018-12-31

XX-ABC11            2018-11-30                        2018-12-31

XX-ABD12            2019-01-31                        2019-03-31

If we look at the result set, it returns only those rows that matches with the right table expression. Project Number XX-ABC13 is missing. CROSS APPLY is equivalent to an INNER JOIN. To be more precise its like a CROSS JOIN with a correlated sub-query).

If we want to return all rows from the left side then we need to apply OUTER APPLY which is equivalent to a LEFT OUTER JOIN.

Resources

https://www.mssqltips.com/sqlservertip/1958/sql-server-cross-apply-and-outer-apply/