如何使用实体框架将数据插入到索引表中 [英] How can I insert data into refrencing table using entity framework

问题描述

我有三个桌子. tbl_area，tbl_item和tbl_areaitemmap.
tbl_area包含数据，无需在此表中插入.

tbl_areaitemmap
mapid-主键
fkareaid-tbl_area(areaid)的前键
fitemid-tbl_item(itemid)的前键


我只想当我将数据插入到tbl_areaitemmap中时，如果该项目存在，则还会在tbl_item anf中插入一个，然后tbl_areaitemmap引用那些id.

像这样?????请告诉我..
using(sampleEntities _entitiesContext = new SampleEntities())
{
var context = _entitiesContext.tbl_areaitemmap;

var obj = new tbl_areaitemmap();
obj.tbl_area_r.AreaId = 7;
obj.tbl_item.pkItemId = 12;
obj.status ="T";

_entitiesContext.AddTotbl_areaitemmap(obj);
试试
{
_entitiesContext.SaveChanges();
返回true;
}
catch(Exception)
{

返回false;
}
}

I having three tables. tbl_area, tbl_item and tbl_areaitemmap.
tbl_area have data and no need to insertion in this table.

tbl_areaitemmap
mapid - primary key
fkareaid - foriegnkey to tbl_area(areaid)
fitemid - foriegnkey to tbl_item(itemid)


I just want when I''m insert data into into tbl_areaitemmap there is also a insertion in tbl_item anf if the item is exist then tbl_areaitemmap refrence to those id.

just like this????? plz tell me..
using(sampleEntities _entitiesContext = new SampleEntities())
{
var context = _entitiesContext.tbl_areaitemmap;

var obj = new tbl_areaitemmap();
obj.tbl_area_r.AreaId =7;
obj.tbl_item.pkItemId = 12;
obj.status = "T";

_entitiesContext.AddTotbl_areaitemmap(obj);
try
{
_entitiesContext.SaveChanges();
return true;
}
catch (Exception)
{

return false;
}
}

推荐答案

如果您尝试上面的代码，那么您将得到一个解决方案.对于您的方案，您需要创建一个存储过程以将值插入表中并调用从实体框架存储p.

if you try the above code then you will get a solution.For your scenario you need create a store procedure for inserting the value in both table and call that store p from entity framework.

我不知道您说的是什么
当我将数据插入到tbl_areaitemmap中时，还会在tbl_item中插入一个，如果该项目存在，则tbl_areaitemmap会引用这些ID.

我已经使用了映射表，它的意思是这样.

首先，您插入tbl_item并获取其itemid.然后插入tbl_area并获取其areaid.
那么您可以添加一个tbl_areaitemmap和两个ID.

则实体框架将自行在内部为您链接对象.

这是样本

int itemid = 0;
tbl_item tableitem = new tbl_item();
tbl_areaitemmap areaitemmaps = new tbl_areaitemmap();

using(sampleEntities _entitiesContext = new SampleEntities())
{
//在此处设置表格项值


//在此处设置tableareaitemmaps值
areaitemmaps.tbl_area_r.AreaId = 7;

//除非tbr_itemId为12，否则您将无法插入Areaitemmap，除非
//如果您尝试添加Areaitemmaps，则ID为12的数据库中存在一个tbl_item
//如果tbl_item.Id不存在，则会抛出外键中断异常
//离开以下行
//areaitemmaps.tbl_item.pkItemId = 12;
areaitemmaps.status ="T";


试试
{
//首先插入tableitem

_entitiesContext.AddTotbl_item(tableitem);
_entitiesContext.SaveChanges();

//然后获取新插入的tableitem的ID并将其分配给areaitemmap
areaitemmap.tbl_item.pkItemId = tableitem.ItemId

//然后插入tableareaitemmap
_entitiesContext.AddTotbl_areaitemmap(areaitemmap);

_entitiesContext.SaveChanges();

//这将使其强制执行您的外键

返回true;
}
catch(Exception)
{

返回false;
}
}

i dont know what you mean when you say
when I''m insert data into into tbl_areaitemmap there is also a insertion in tbl_item and if the item is exist then tbl_areaitemmap refrence to those id.

i have used mapping tables and its meant to be done like this.

first you insert the tbl_item and get its itemid. then insert tbl_area and get its areaid.
then you can add a tbl_areaitemmap with the two ids you just got.

then entity framework will internally link the objects for you by itself.

here is sample

int itemid = 0;
tbl_item tableitem = new tbl_item();
tbl_areaitemmap areaitemmaps = new tbl_areaitemmap();

using(sampleEntities _entitiesContext = new SampleEntities())
{
//setup tableitem values here


//setup tableareaitemmaps values here
areaitemmaps.tbl_area_r.AreaId =7;

//you wont be able to insert a areaitemmap with tbl_itemId of 12 unless
//a tbl_item exists in database with a Id of 12. if you try to add a areaitemmaps
//with tbl_item.Id of a non existing one it will throw a foreign key broken exception
// leave the following line
//areaitemmaps.tbl_item.pkItemId = 12;
areaitemmaps.status = "T";


try
{
//firstly insert the tableitem

_entitiesContext.AddTotbl_item(tableitem);
_entitiesContext.SaveChanges();

//then get the Id of newly inserted tableitem and assign it to the areaitemmap
areaitemmap.tbl_item.pkItemId = tableitem.ItemId

//then insert tableareaitemmap
_entitiesContext.AddTotbl_areaitemmap(areaitemmap);

_entitiesContext.SaveChanges();

//this will make it enforce your foreign key

return true;
}
catch (Exception)
{

return false;
}
}

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