Question

我有一个名为＆＃34; UniversalClientSearch＆＃34;的搜索方法。并位于datahandler类中。该方法根据列中的数据和要在该列中搜索的内容搜索表中的数据，然后该方法必须返回一个表变量，以便在我的一个表单上的datagridview中使用。

我已经创建了一个LinQ to SQL语句来获取我想要的数据行，并保存在var ReturnSearchQuery中，但我不知道如何将该查询转换为Table的变量，表名为tbclient。

        //Fields
        private DataAccessDataContext db;

        //Constructor
        public Datahandler()
        {
            this.db = new DataAccessDataContext();
        }

        //Method
        public Table<tbClient> UniversalClientSearch(string SearchType, string SearchParameter)
        {
            //This is just here to initialize the variable so it can be changed in the switch
            var ReturnSearchQuery = from Clients in db.tbClients
                                    select Clients;

            //Filters Query based on what column to search
            switch (SearchType)
            {
                case "Client_ID":
                    ReturnSearchQuery = from Clients in db.tbClients
                        where Clients.Client_ID == int.Parse(SearchParameter)
                        select Clients;
                    break;

                case "Client_Name":
                    ReturnSearchQuery = from Clients in db.tbClients
                        where Clients.Client_Name.Contains(SearchParameter)
                        select Clients;
                    break;

                case "Client_Address":
                    ReturnSearchQuery = from Clients in db.tbClients
                        where Clients.Client_Address.Contains(SearchParameter)
                        select Clients;
                    break;

                case "Contact_Number":
                    ReturnSearchQuery = from Clients in db.tbClients
                        where Clients.Contact_Number.Contains(SearchParameter)
                        select Clients;
                    break;

                case "Contact_Email":
                    ReturnSearchQuery = from Clients in db.tbClients
                        where Clients.Contact_Email.Contains(SearchParameter)
                        select Clients;
                    break;

                case "Client_Type":
                    ReturnSearchQuery = from Clients in db.tbClients
                        where Clients.Client_Type == SearchParameter
                        select Clients;
                    break;
            }

            //Make new table to be returned later
            Table<tbClient> ReturnClientsTable = new Table<tbClient>();

            foreach (var item in ReturnSearchQuery)
            {
                //Query has to be converted to Table<tbClient>
            }

            //Table return to be used in datagridview
            return ReturnClientsTable;
        }

Answer 1

代码中的

IQueryable<tbClient>类型为// The SQL query isn't run yet IQueryable<tbClient> ReturnSearchQuery = from Clients in db.tbClients where <some condition> select Clients;：

IQueryable

由于延迟执行，在枚举// Convert the IQueryable to a list. Here, the SQL query is run. List<tbClient> clients = ReturnSearchQuery.ToList();之前不会执行SQL查询。

DataGridView

最后，您可以使用.DataSource将客户列表绑定到var d = new DataGridView(); d.DataSource = clients;：

sanitize

使用LinQ to SQL返回Table <tablename>

1 个答案: