Home > Linq > Insert, Update , Select and Delete using Linq

Insert, Update , Select and Delete using Linq

July 14, 2009

Hi try this example :-

NorthwindDataContext ctx = new NorthwindDataContext();

//*** Get a Single Row by ID with LINQ
//Returns a single row from the database
private Product GetSingleRowExample1(int productID)
{
Product product = (from p in ctx.Products
where p.ProductID == productID
select p).First();
return product;
}

//Returns a single row from the database (lambda)
private Product GetSingleRowExample2(int productID)
{
return ctx.Products.Single(p => p.ProductID == productID);
}

//*** Get All Rows

//Retrieves all product categories

private void GetAllProductCategories()
 {
 gridResult.DataSource = ctx.ProductCategories;
 gridResult.DataBind();
 }

//*** Insert a Row and Return The Generated ID

protected void btnInsertProductCategory_Click(object sender,
EventArgs e)
{
ProductCategory productCategory = new ProductCategory();
productCategory.Name = “Sample Category”;
productCategory.ModifiedDate = DateTime.Now;
productCategory.rowguid = Guid.NewGuid();
int id = InsertProductCategory(productCategory);
lblResult.Text = id.ToString();
}
//Insert a new product category and return the generated ID (identity value)
private int InsertProductCategory(ProductCategory productCategory)
{
ctx.ProductCategories.InsertOnSubmit(productCategory);
ctx.SubmitChanges();
return productCategory.ProductCategoryID;
}

//*** Update a Row
The built-in change tracking in LINQ automatically determines, if connecting to the database is necessary. If an object is modified, LINQ then generates the necessary UPDATE-statemens automatically.

//Retrieves and updates product category with ID of 4

protected void btnUpdateProductCategory_Click(object sender, EventArgs e)
{
ProductCategory productCategory =ctx.ProductCategories.Single(pc => pc.ProductCategoryID == 4);
UpdateProductCategory(productCategory);
}
//Updates the given product category
private void UpdateProductCategory(ProductCategory productCategory)
{
productCategory.ModifiedDate = DateTime.Now;
productCategory.Name = productCategory.Name + " test";
ctx.SubmitChanges();
}

//*** Delete a Row
Deleting a row is simple.
You could also remove several rows with the DeleteAllOnSubmit-method.

protected void btnDeleteProductCategory_Click(object sender,EventArgs e)
{
ProductCategory productCategory = ctx.ProductCategories
.Single(pc => pc.ProductCategoryID == 5);
DeleteProductCategory(productCategory);
}

//Deletes the given product category
private void DeleteProductCategory(ProductCategory productCategory)
{
ctx.ProductCategories.DeleteOnSubmit(productCategory);
ctx.SubmitChanges();
}

Hope this helps
Good Luck

Advertisements
Categories: Linq
%d bloggers like this: