Such a linq

 
Var query1.=the from t in dt_return_all_x1 AsEnumerable () 
Group t by new 
{
T1=t.F ield (" ID "production batches), t2=t.F ield (" ID ") 
} 
Into m 
Select new 
{
Production batch number ID=m.K ey. T1, product ID=m.K ey. T2, number=Margaret spellings um (n=& gt; N.F ield (" number ")) 
}; 

I use the following method converts the datatable,
The DataTable dt=ToDataTable (query1. ToList ());

 
Public DataTable ToDataTable (List Entitys) 
{
////check collection entity can't be empty 
If (entitys==null | | entitys. Count & lt; 1) 
{
Throw new Exception (" need to convert collection is empty "); 
} 

//remove the first entity all Propertie 
Type entityType=entitys [0]. GetType (); 
PropertyInfo [] entityProperties=entityType. The GetProperties (); 

//generate DataTable structure 
The DataTable dt=new DataTable (); 
for (int i=0; I & lt; EntityProperties. Length; I++) 
{
Dt. Columns. The Add (entityProperties [I]. Name, entityProperties [I] PropertyType); 
} 

//add all of the entity to the DataTable 
Foreach (object entity in entitys) 
{
Object [] entityValues=new object [entityProperties Length]. 
for (int i=0; I & lt; EntityProperties. Length; I++) 
{
EntityValues [I]=entityProperties [I] GetValue (entity, null); 

} 
Dt. Rows. The Add (entityValues); 
} 
Return dt. 
} 

If not empty set have records of the linq query, can return to normal a datatable,
If linq queries to the results, and it throws an exception,

How do I do it: when the linq query is an empty set, you can generate a field, only empty DataTable without record?
Production batch number ID product ID number

CodePudding user response:

Set the Count is zero, also create the DataTable can, if there is data, insert data to the DataTable

CodePudding user response:

Set the count of 0,
//remove the first entity all Propertie
Type entityType=entitys [0]. GetType ();
This code will be out of the question, "index beyond the scope of"

CodePudding user response:

Type entityType=entities. GetType (). GetGenericArguments () [0];
So we can get type, regardless of the entities have the data

CodePudding user response:

refer to the second floor qg1977 response:

set the count of 0,
//remove the first entity all Propertie
Type entityType=entitys [0]. GetType ();
This code will be out of the question, "index beyond the scope of"

Should use the typeof (T),

CodePudding user response:

There is not one of them is new