如何在DataColumn.Expression中使用IF / ELSE或CASE? [英] How do I use IF/ELSE or CASE In DataColumn.Expression?
本文介绍了如何在DataColumn.Expression中使用IF / ELSE或CASE?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有一个表,其中有1列:'Status'
我想在另一列中添加'Action',其值如下:如果Status ='Yes'然后Action ='Go',否则,Action ='Stop'。我使用以下代码在操作列中添加了它,但没有用:
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");
推荐答案
您要查找的表达式是:
IIF( [Status] = 'Yes', 'Go', 'Stop' )
DataTables不支持标准SQL CASE
语句,也不支持 IF ... ELSE 声明。您必须使用内联if函数: IIF
DataTables do not support standard SQL CASE
statements, nor do they support "IF... ELSE" statements. You must use the inline-if function: IIF
请参见 DataColumn.Expression属性(MSDN)
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