Question

如何在 ~~Ado.Net~~ WCF数据服务中编写'In'查询？我试过以下代码。

IList<int> orderIds = new List<int> { 59810, 59811, 59812, 59813, 59814 };
var lstorders = _context.Orders
                        .Where(o => orderIds.Contains(o.customerId))
                        .ToList<Orders>();

但上面的代码不起作用。我收到了以下错误。

测试'MyTest'失败：System.NotSupportedException：The 表达式（（[10007] .customerId！= null）而且值（System.Collections.Generic.List 1[System.Int32]).Contains([10007].customerId.Value)) is not supported. at System.Data.Services.Client.ExpressionWriter.ExpressionToString(DataServiceContext context, Expression e) at System.Data.Services.Client.UriWriter.VisitQueryOptionExpression(FilterQueryOptionExpression fqoe) at System.Data.Services.Client.UriWriter.VisitQueryOptions(ResourceExpression re) at System.Data.Services.Client.UriWriter.VisitResourceSetExpression(ResourceSetExpression rse) at System.Data.Services.Client.DataServiceALinqExpressionVisitor.Visit(Expression exp) at System.Data.Services.Client.UriWriter.Translate(DataServiceContext context, Boolean addTrailingParens, Expression e, Uri& uri, Version& version) at System.Data.Services.Client.DataServiceQueryProvider.Translate(Expression e) at System.Data.Services.Client.DataServiceQuery 1.Execute（）在System.Data.Services.Client.DataServiceQuery 1.GetEnumerator() at System.Collections.Generic.List 1..ctor（IEnumerable 1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable 1 源）

Answer 1

这可能会有所帮助。

Select entities where ID in int array - WCF Data Services, LINQ

Answer 2

WCF数据服务'WHERE IN'，'WHERE NOT IN'扩展方法sample

如何在WCF数据服务中编写“In”查询？

2 个答案: