How do I use IF/ELSE or CASE In DataColumn.Expression?

c# sql expression datacolumn
J - C Sharper picture J - C Sharper · Oct 11, 2013 · Viewed 17.7k times · Source

I have a table with 1 column: 'Status' I want to add in another column named 'Action', its value will be as follow: if Status = 'Yes' Then Action = 'Go', otherwise, Action = 'Stop'. I used this following code to add in column 'Action' but it didn't work:

myDataTable.Columns.Add("Action", typeof(string), "IF [Status] = 'Yes' THEN 'Go' ELSE 'Stop' END");

Answer

JDB still remembers Monica picture JDB still remembers Monica · Oct 11, 2013

The expression you are looking for is:

IIF( [Status] = 'Yes', 'Go', 'Stop' )

DataTables do not support standard SQL CASE statements, nor do they support "IF... ELSE" statements. You must use the inline-if function: IIF

See DataColumn.Expression Property (MSDN)

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