Linq 查询仅返回数组的第一项

Question

让字符串项目等于“p1,p2,p3”，并且在数据库中每个项目的标识符存在如下 p1 = 1 ,p2 = 2, p3 = 3 。在我的查询中仅返回列表中的第一个项目，任何为什么？

private List<int> getProjects(string projects)
    {

        String[] projectArray = projects.Split(',');

        QMOIIEntities db = new QMOIIEntities();

        var projectList = db.wbs_projects
          .Where(x => projectArray.Contains(x.prjName))
          .Select(x => x.prjID).ToList();

        return projectList;
    }

**更新 字符串中的空格

String[] projectArray = projects.Split(',');

这个问题是我更改为的

 String[] projectArray = projects.Trim().Split(',');

Answer 1

以下代码使用与您在问题中提到的相同逻辑。我创建了虚拟数据。该代码的行为符合预期，即输出是与每个 prjName 对应的 prjID。

void Main()
{
    string projects = "p1,p2,p3";
    List<string> projectArray = projects.Split(',').ToList();

    TestEntities db = new TestEntities();
    db.wbs_projects = new List<TestEntities>();
    db.wbs_projects.Add(new TestEntities(){prjName = "p1",prjID="Test1"});
    db.wbs_projects.Add(new TestEntities(){prjName = "p2",prjID="Test2"});
    db.wbs_projects.Add(new TestEntities(){prjName = "p3",prjID="Test3"});

    var projectList = db.wbs_projects
      .Where(x => projectArray.Contains(x.prjName))
      .Select(x => x.prjID).ToList();

    foreach(var item in projectList)
    {
        Console.WriteLine(item);//Test1,Test2,Test3
    }

}

public class TestEntities
{   
    public List<TestEntities> wbs_projects{get;set;}

    public string prjName{get;set;}
    public string prjID{get;set;}
}