以下有何不同之处
CreateQuery() ExecuteFunction(), ExecuteStoreQuery() and ExecuteStoreCommand()
据我所知,CreateQuery用于Entity SQL,其余的方法用于在DB中定义的sql函数或存储过程.
根据ObjectContext类元数据,它们如下:
CreateQuery():Creates an System.Data.Objects.ObjectQuery<T> in the current object context by using the specified query string.
Returned -> System.Data.Objects.ObjectQuery<T>
ExecuteFunction(): Executes a stored procedure or function that is defined in the data source and expressed in the conceptual model; discards any results returned from
the function; and returns the number of rows affected by the execution.
Returned -> The number of rows affected.
This has an overloaded version which return -> The entity …我试图使用ExecuteStoreQuery像这样的linq 方法从表中删除多行
string query = "delete from IMPORTStatistics where districtid='" + districtId + "'";
db.ExecuteStoreQuery<int>(query);
但它抛出了这个例外
"The data reader has more than one field. Multiple fields are not valid for EDM primitive types."
我究竟做错了什么？
仅供参考,我使用的是MySql.
我的数据库中有一个存储过程,它接受一个表值参数,一个包含单个整数Id列的IdTable对象列表.
我有一个数据库实体模型,想要做以下...
ProjectEntities projectEntities = new ProjectEntities ();
DataTable stationIds = new DataTable();
stationIds.Columns.Add("Id");
stationIds.Rows.Add(1);
stationIds.Rows.Add(2);
SqlParameter parameter = new SqlParameter("@stationIds",stationIds);
parameter.TypeName = "IdTable";
var parameters = new object[] {parameter};
var results = projectEntities .ExecuteStoreQuery<ProjectSummary>("exec ProjectSummary", parameters);
var count = results.Count();
当它应该返回一堆ProjectSummary实体时,它会运行并且不返回任何结果.
当我在SQL事件探查器中对此进行分析时,我得到以下内容
declare @p3 IdTable
insert into @p3 values(N'1')
insert into @p3 values(N'2')
exec sp_executesql N'exec ProjectSummary',N'@stationIds [IdTable] READONLY',@stationIds=@p3
如果我声明存储过程
ALTER PROCEDURE [dbo].[ProjectSummary]
@stationIds [dbo].[IdTable] READONLY
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from …在entityframework中,我们可以使用ExecuteStoreQuery或ExecuteStoreCommand来执行sql查询.那么它们之间有什么区别(哪种情况不同)？
谢谢.