c# - 在数据表上进行选择时出现异常

Question

这是我的代码

var compainNames = (from row in DTgraph.AsEnumerable()
                                group row by row.Field<string>("Campaign") into grp
                                select new
                                {
                                    CampaignName = grp.Key
                                }).ToList();

 var dataForOneCampaint = DTgraph.Select("Campaign = " + compainNames[i].ToString()).ToList();

其中 DTgraph 是数据表。

我遇到了这个异常:

Cannot interpret token '{' at position 12.

你能帮忙吗？

我调试后可以看到 compainNames 有 3 个字符串

这一行的异常

 var dataForOneCampaint = DTgraph.Select("Campaign = " + compainNames[i].ToString()).ToList();

Answer 1

DataTable.Select方法使用与 DataColumn.Expression property 相同的规则用于创建过滤器。

来自它的文档；

User-Defined Values

User-defined values may be used within expressions to be compared with column values. String values should be enclosed within single quotation marks (and each single quotation character in a string value has to be escaped by prepending it with another single quotation character).

我相信你可以使用；

var dataForOneCampaint = DTgraph
                        .Select("Campaign = '" + compainNames[i].ToString() + "'")
                        .ToList();

或者使用String.Format作为Felipe mentioned .