How to Remove Empty Column After Mail Merge in Core Word document?

Syncfusion Essential DocIO is a .NET Word library used to create, read, edit, and convert Word documents programmatically without Microsoft Word or interop dependencies. Using this library, you can remove an empty column after mail merge in a Word document using C#.

Follow the steps below:

• Find the table and column with the merge field.
• Execute the mail merge with an event handler.
• In the event handler, check if the merge field has a value.
• Use a Boolean flag to indicate whether the merge field contains a value.
• After the mail merge, remove the column if the merge field is empty.

Steps to remove the empty column after mail merge in Word document:

1. Create a new .NET Core console application project.
2. Install the Syncfusion.DocIO.Net.Core NuGet package as a reference to your project from NuGet.org.
   
   

3. Include the following namespaces in Program.cs file
   C#

using Syncfusion.DocIO.DLS;
using Syncfusion.DocIO; 

4. Use the following code example to remove the empty column after mail merge in Word document.
   C#

//Boolean to check whether the merge field has value.
public static bool hasCostValue = false;
//Cell index of the merge field.
public static int cellIndex;
//Creates new Word document instance for Word processing.
using (WordDocument document = new WordDocument())
{
   //Opens the Word template document.
   Stream docStream = File.OpenRead(Path.GetFullPath(@"Data/Template.docx"));
   document.Open(docStream, FormatType.Docx);
   docStream.Dispose();
   //Get the table.
   WTable table = GetColumnIndex(document);
   //Get the data set.
   DataSet ds = GetData();
   //Even handler to verify if a field has a valid value.
   document.MailMerge.MergeField += new MergeFieldEventHandler(MergeField_TaskCost);
   //Execute Mail Merge with groups.
   document.MailMerge.ExecuteGroup(ds.Tables["Task_CostList"]);
   if (!hasCostValue)
   {
       //Remove the empty column.
       RemoveColumn(table);
   }
   //Saves and closes the Word document.
   docStream = File.Create(Path.GetFullPath(@"Output/Output.docx"));
   document.Save(docStream, FormatType.Docx);
   docStream.Dispose();
}

5. Use the following helper method to get the column index of a specific merge field within the Word document.
   C#

/// <summary>
/// Get the column index.
/// </summary>
private static WTable GetColumnIndex(WordDocument document)
{
   WTable table = null;
   //Get the merge field.
   WMergeField mergeField = document.FindItemByProperty(EntityType.MergeField, "FieldName", "Cost") as WMergeField;
   if (mergeField != null)
   {
       //Check whether the merge field is present inside a table cell.
       if (mergeField.OwnerParagraph.IsInCell)
       {
           WTableCell cell = mergeField.OwnerParagraph.OwnerTextBody as WTableCell;
           //Get the column index.
           cellIndex = cell.GetCellIndex();
           table = cell.OwnerRow.Owner as WTable;
       }
   }
   return table;
}

6. Use the following helper method to get the data needed to perform a mail merge.
   C#

/// <summary>
/// Gets the data to perform mail merge.
/// </summary>
private static DataSet GetData()
{
   // Create a DataSet.
   DataSet ds = new DataSet();
   //List of Syncfusion products name.      
   string[] products = { "Task 1", "Task 2", "Task 3", "Task 4", "Task 5" };
   //Add new Tables to the data set.
   DataRow row;
   ds.Tables.Add();
   ds.Tables.Add();
   //Add fields to the Task_CostList table.
   ds.Tables[0].TableName = "Task_CostList";
   ds.Tables[0].Columns.Add("Task");
   ds.Tables[0].Columns.Add("Cost");
   int count = 0;
   //Insert values to the table row.
   foreach (string product in products)
   {
       row = ds.Tables["Task_CostList"].NewRow();
       row["Task"] = product;
       ds.Tables["Task_CostList"].Rows.Add(row);
       count++;
   }
   return ds;
}

7. Use the following helper method to remove the column.
   C#

/// <summary>
/// Remove the column.
/// </summary>
private static void RemoveColumn(WTable table)
{
   //Iterate through all rows.
   for (int i = table.Rows.Count - 1; i >= 0; i--)
   {
       //Remove the cell present in the cellIndex.
       table.Rows[i].Cells.RemoveAt(cellIndex);
   }
}

8. Use the following helper method to process a merge field event to verify if a field has a valid value and set a flag accordingly.
   C#

/// <summary>
/// Method to handle MergeField event to verify field value and set a flag.
/// </summary>  
private static void MergeField_TaskCost(object sender, MergeFieldEventArgs args)
{
    if ( args.FieldName == "Cost" && hasCostValue && args.FieldValue != null
        && args.FieldValue != DBNull.Value && args.FieldValue != string.Empty)
    {
        hasCostValue = true;
    }
}

You can download a complete working sample to remove an empty column after mail merge in a Word document from the GitHub.

By executing the program, you will get the Word document as follows.

Conclusion
I hope you enjoyed learning about how to remove an empty column after mail merge in a Word document.

You can refer to our ASP.NET Core DocIO feature tour page to know about its other groundbreaking feature representations and documentation, and how to quickly get started for configuration specifications. You can also explore our ASP.NET Core DocIO example to understand how to create and manipulate data.

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