Question

我有一个字符串列表

List<string> firstNames = new List<string>();

我有一个查询结果

var contacts = (from p in datacontext.Contact)

如何根据字符串列表查询原始结果（联系人）？

select * from contacts where contacts.firstname like firstNames

类似

firstNames.Any(x=>x.contacts.Contains(x))

Answer 1

您应该将名字推送到数据库查询中，如下所示：

var contacts = dataContext.Contacts.Where(c => firstNames.Contains(c.FirstName));

现在你在样本查询中使用了“like”，所以也许你想要：

var contacts = dataContext.Contacts
                     .Where(c => firstNames.Any(f => c.FirstName.Contains(f)));

如果你能提供一些具体的例子，那将有所帮助。

编辑：如果您真的将数据库中的所有联系人拉回（例如）List<Contact> contacts，那么您可以使用：

var matchingContacts = from contact in contacts
                       join name in firstNames
                       on contact.FirstName equals name
                       select contact;

Answer 2

首先，访问此链接，下载该类并将其添加到App_Code文件夹：http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx

然后一定要添加“using System.Linq.Dynamic;”

然后构建您的查询：

    DatabaseDataContext db = new DatabaseDataContext();
    List<string> firstNames = new List<string>();

    //--- loop through names and build a where query
    string WhereClause = string.Empty;
    for (int i = 0; i < firstNames.Count(); i++)
    {
        string s = firstNames[i].ToLower();

        if (i != Communities.Length - 1)
            WhereClause += "FirstName.ToLower().Contains(\"" + s + "\") OR "; //--- first name is the field name in the db
        else
            WhereClause += "FirstName.ToLower().Contains(\"" + s + "\")";
    }

    //--- execute query and pass the dynamic where clause
    IQueryable contacts = db.Contacts
                          .Where(WhereClause)
                          .OrderBy("FirstName");

祝你好运！

Linq - 针对字符串列表查询查询结果

2 个答案: