var query = from o in db.Orders join e in db.Employees on o.EmployeeID equals (int?)e.EmployeeID select new { o.OrderID, e.FirstName }; 每个示例中都使用 equals 查询关键字。 还可使用模式匹配,其中包括 is null 和is not null 的模式。 不
http://stackoverflow.com/questions/3020442/linq-joining-in-c-sharp-with-multiple-conditions 如果要达到这个sql的效果: SELECT*FROMtable1 aLEFTJOINtable2 bONa.col1=b.key1ANDa.col2=b.key2ANDb.from_date<=now()ANDb.deleted=0; 可以这样: varquery = (fromxincontext.table1 join yincontext.table...
what information to retrieve from the data source or sources. Optionally, a query also specifies how that information should be sorted, grouped, and shaped before being returned. A query is stored in a query variable and initialized with a query expression. You useC# query syntaxto write ...
varcategoryQuery =fromcatincategoriesjoinprodinproductsoncatequalsprod.Categoryselectnew{ Category = cat, Name = prod.Name }; 还可以通过将join操作的结果存储到一个临时变量中,然后使用into关键字来执行组联接。 有关详细信息,请参阅join 子句。
Optionally, a query also specifies how that information should be sorted, grouped, and shaped before being returned. A query is stored in a query variable and initialized with a query expression. You use C# query syntax to write queries. The query in the previous example returns all the even...
Fill DataTable Using Entity Framework using linq Query with all Possible way? Filter Upper case records using DataTable.DefaultView.RowFilter Filtering DataTable Against Second DataTable Find Duplicate Rows in DataTable using LINQ via VB.Net syntax Finding a specific record when multiple records are ...
LINQ includes another join variation that generates hierarchical query results. In such queries, one of the fields in each resultant record will be a collection that contains multiple results. This syntax allows LINQ to return a list of all authors, one author per row, where each author record...
The examples in this topic demonstrate how to use theJoinmethod to query aDataSetusing the method query syntax. TheFillDataSetmethod used in these examples is specified inLoading Data Into a DataSet. The examples in this topic use the Contact, Address, Product, SalesOrderHeader, and SalesOrderDet...
You use multiple Join clauses with filter clauses to create a result that is filtered on attributes from several entities.The following sample shows how to create a LINQ query that works with two entities and filters the result based on values from each of the entities....
This query does not use the query expression syntax, but rather uses the functional style of IEnumerable<string>.OrderBy(): // Create CultureInfo for Danish in Denmark. CultureInfo danish = new CultureInfo("da-DK"); // Create CultureInfo for English in the U.S. CultureInfo american = new ...