As in previous article explained that how we can create the
entity frame work classes and how we can use it.
Refer below link for the same;
Now in This Session will
explain you how to perform the insert update delete operation in entity
framework.
Suppose you have the table like below
You have already run the wizard and you got all the classes and
helping classes of entity frame work,
To display the list of records into the grid, you need to
use the command in Linq query to get the records of entity framework select
items.
EntityFramework Select Operation
Get the records into data base through entity frame work.
It will be like below; As in below code I have joined the
another class also to get the consolidate response of other class.
public List<BookDetails> GetBookDetail()
{
using (LibraryManagementSystemEntities obj = new LibraryManagementSystemEntities())
{
return (from oBook in obj.BookDetails
join oCat in obj.BookCategories on oBook.BookCategoryId equals oCat.BookCategoryId
select new BookDetails
{
BookDetailId = oBook.BookDetailId,
BookName =
oBook.BookName,
BookAuthor =
oBook.BookAuthor,
Price =
oBook.Price,
NoofBookAvilable =
oBook.NoofBookAvilable,
BookCategory = new BookCategorys() {BookCategoryId =
oCat.BookCategoryId ,BookCategory
= oCat.BookCategoryName },
NoOfbooks =
oBook.NoOfbooks,
CreatedDate =
oBook.CreatedDate
}).ToList();
}
}
EntityFramework Insert Operation
Inserting the records into data base through entity frame
work.
Above two lines of code help to insert the records into
database. We will frame the object and call the method registerBookDetails and
pass the Object of bookdetail as an argument.
public int RegisterBookDetail(BookDetails oName)
{
using (LibraryManagementSystemEntities obj = new LibraryManagementSystemEntities())
{
BookDetail oData = new BookDetail();
oData.BookName =
oName.BookName;
oData.BookAuthor =
oName.BookAuthor;
oData.Price = oName.Price;
oData.NoOfbooks =
oName.NoOfbooks;
oData.NoofBookAvilable =
oName.NoOfbooks;
oData.BookCategoryId =
oName.BookCategory.BookCategoryId ;
oData.CreatedBy =
oName.CreatedBy;
oData.CreatedDate = DateTime.Now;
oData.ModifiedBy = DateTime.Now;
obj.BookDetails.Add(oData);
return obj.SaveChanges();
}
}
EntityFramework Update Operation
Updating the records into data base through entity frame
work.
Before call the savechanges method we need to just query
the collection of entity frame work and on the result only need to find the
collections and call the savechanges method.
public int UpdateBookDetail(BookDetails oName)
{
using (LibraryManagementSystemEntities obj = new LibraryManagementSystemEntities())
{
var oData = obj.BookDetails.First(i => i.BookDetailId ==
oName.BookDetailId);
oData.BookName =
oName.BookName;
oData.BookAuthor =
oName.BookAuthor;
oData.Price = oName.Price;
oData.NoOfbooks =
oName.NoOfbooks;
oData.NoofBookAvilable =
oName.NoOfbooks;
oData.BookCategoryId =
oName.BookCategory.BookCategoryId;
oData.ModifiedBy = DateTime.Now;
return obj.SaveChanges();
}
}
EntityFramework Delete Operation
Delete the records into data base through entity frame
work.
Just need to query the object that you want to delet and
pass that object to remove method and after that you just need to call the Save
Changes method.
public int DeleteBookDetail(int BookId)
{
using (LibraryManagementSystemEntities obj = new LibraryManagementSystemEntities())
{
var oSelect = obj.BookDetails.First(i => i.BookDetailId ==
BookId);
obj.BookDetails.Remove(oSelect);
return obj.SaveChanges();
}
}
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