Dim query = From st In db.Student Select New With { .stName = st.FirstName & " " & st.LastName, _ .BonusHours = (From ts In st.TimeSheets Join tr in db.TimeRecord On tr.TimeSheetId Equals ts.TimeSheetId _ Where ts.IsActive = True And tr.IsValid = True _ Group By key =...
protected void Page_Load(object sender, EventArgs e) { using (NorthWindEntities1 db = new NorthWindEntities1()) { var query = from ot in db.tblStudents join v in db.tblAwardsTables on ot.school equals v.school join c in db.tblAccountTables on v.account_number equals c.account_number ...
Join JOIN连接组合两个表中的字段记录,包括三种: INNER JOIN运算式:连接组合两个表中的字段记录。 LEFT JOIN运算式:连接组合两个表中的字段记录,并将包含了LEFT JOIN左边表中的全部记录。 RIGHT JOIN运算式:连接组合两个表中的字段记录,并将包含了RIGHT JOIN右边表中的全部记录。 INNER JOIN设定两个表相关连的...
在Linq中,可以使用join关键字来进行多个表的连接操作。具体的语法如下: 代码语言:csharp 复制 var query = from leftTable in leftDataSource join rightTable in rightDataSource on leftTable.Key equals rightTable.Key into joinedTables from result in joinedTables.DefaultIfEmpty() select new { // 选择需要...
通过Linq的join关键字,我们将两个数据源customers和orders连接起来,连接条件是customer.Id和order.CustomerId相等。最后,我们使用select关键字选择需要的字段,并通过foreach循环遍历查询结果。 这种连接操作在实际开发中非常常见,特别是在关系型数据库中进行关联查询时。通过Linq的连接操作,我们可以方便地获取到相关联的数据...
join rinds.Tables["Role"].AsEnumerable() on u.Field<int>("RoleId") equals r.Field<int>("Id") selectnew { Id=u.Field<int>("Id"), Name=u.Field<string>("Name"), RoleId=r.Field<int>("Id"), RoleName=r.Field<string>("Name") ...
2019-12-23 09:28 −DataTable dtMap = null;//创建DataTable DataView dv = dsMap.Tables[0].DefaultView;//dsMap为DataSet数据源 dv.Sort = "r_code desc";//r_code为排序... Bands 0 394 inner join(内连接)、left join(左连接)、right join(右连接)、full join(全连接)区别 ...
Explicit Join Syntax (In addition to standard LINQ join syntax) CTE Support Bulk Copy/Insert Window/Analytic Functions Merge API Extensibility: Ability to Map Custom SQL to Static Functions See Github.io documentation for more details. Code examples and demos can be found here or in tests. Rel...
DataSet ds = new DataSet(); ds.Locale = CultureInfo.InvariantCulture; FillDataSet(ds); DataTable orders = ds.Tables["SalesOrderHeader"]; DataTable details = ds.Tables["SalesOrderDetail"]; var query = from order in orders.AsEnumerable() join detail in details.AsEnumerable() on order.Field<...
quantityTables = (from dr4 in dt4.AsEnumerable() join dr3 in dt3.AsEnumerable() on new { t = dr4.Field<string>("T"), sn = dr4.Field<decimal>("SN"), unit = dr4.Field<string>("UNIT"), work_resource_no = dr4.Field<decimal>("WORK_RESOURCE_NO") ...