public static int srno = 1;
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
getdata();
}
}
public void getdata()
{
var mydir = new DirectoryInfo("D:\\").GetFiles();
// 1.
//var q = from file in mydir
// where file.Length > 10000
// select new {
// file.Name,
// file.Length,
// file.CreationTime
// };
//2.
var q = from file in mydir
//where file.Name.StartsWith("c") orderby file.Length descending
// where file.Name.
select new
{
file.Name,
file.Length,
file.CreationTime
};
foreach (var i in q)
{
Response.Write( srno +". " + i.Name + "-----" +i.Length + "-----" + i.CreationTime + "</br>");
srno += 1;
}
}
*******************************************************************************
LINQ PRACTISE SNIPPETS 1
*******************************************************************************
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
getdata();
showalldata();
}
}
public void showalldata()
{
using (NWSQLClassDataContext ctx = new NWSQLClassDataContext())
{
var q = from p in ctx.Products
orderby p.ProductName
select new {p.CategoryID,p.Category.CategoryName,
p.ProductName,p.UnitPrice, p.Discontinued
};
grd.DataSource = q;
grd.DataBind();
}
}
public void getdata()
{
//
// NWSQLClassDataContext ctx = new NWSQLClassDataContext();
//Product p = ctx.Products.First(a => a.CategoryID == 1);
//Response.Write(p.ProductName.ToString());
using (NWSQLClassDataContext ctx = new NWSQLClassDataContext())
{
var q = from p in ctx.Categories
select new { p.CategoryID, p.CategoryName };
ddlcat.DataSource = q;
ddlcat.DataTextField = "CategoryName";
ddlcat.DataValueField = "CategoryID";
ddlcat.DataBind();
}
}
protected void ddlcat_SelectedIndexChanged(object sender, EventArgs e)
{
Int32 catid = Convert.ToInt32(ddlcat.SelectedItem.Value.ToString());
using (NWSQLClassDataContext ctx = new NWSQLClassDataContext())
{
var q = from p in ctx.Products
where p.CategoryID == catid
select new {p.CategoryID,p.Category.CategoryName,
p.ProductName,p.UnitPrice,p.Discontinued
};
grd.DataSource = q;
grd.DataBind();
}
}
protected void btnInsert_Click(object sender, EventArgs e)
{
using (NWSQLClassDataContext ctx = new NWSQLClassDataContext())
{
Product p = new Product {CategoryID=1, ProductName="MyNewProduct1",
UnitPrice= 4.43m
};
ctx.Products.InsertOnSubmit(p);
ctx.SubmitChanges();
showalldata();
}
}
protected void btnDelete_Click(object sender, EventArgs e)
{
// Delete product using your custom stored procedure.
using (NWSQLClassDataContext ctx = new NWSQLClassDataContext())
{
// Product p = ctx.Products.Where(a => a.ProductID == 79).First();
// ctx.Products.InsertOnSubmit(p);
// ctx.SubmitChanges();
// ctx.Products.DeleteOnSubmit(p);
//ctx.SubmitChanges();
int? intresult=0;
var q = ctx.usp_DeleteProductByProductID(83);
int val =(int)q.ReturnValue;
int x = (int)ctx.usp_DeleteProductByProductID(83).ReturnValue; //for this use return in sp also
showalldata();
}
}
}
*******************************************************************************
LINQ PRACTISE SNIPPETS 2
*******************************************************************************
public static int srno = 1;
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
// getdata();
// getdata_2();
// getdata_3();
// getdata_4();
// getdata_5();
getdata6();
}
}
public void getdata()
{
// int[] myarr = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
int[] myarr = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
var q = from item in myarr
where item > 5 orderby item descending
select item;
foreach(int i in q)
{
Response.Write(i + "</br>");
}
}
public void getdata1()
{
XElement xe = new XElement("abc");
// int[] myarr = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
int[] myarr = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
var q = from item in myarr
where item > 5
orderby item descending
select item;
foreach (int i in q)
{
Response.Write(i + "</br>");
}
}
private class vikas
{
public string Name;
public long Length;
public System.DateTime CreationTime;
}
public void getdata_2()
{
var mydir = new DirectoryInfo("D:\\").GetFiles();
var q = from item in mydir// vikas in mydir
where item.Length > 1000 orderby item.Name, item.Length descending
select new vikas
{
Name = item.Name,
Length = item.Length,
CreationTime = item.CreationTime
};
foreach (var item in q) // (vikas vk in q)
{
// Response.Write(srno + ". " + vk.Name + "-----" + vk.Length + "-----" + vk.CreationTime + "</br>");
Response.Write(srno + ". " + item.Name + "-----" + item.Length + "-----" + item.CreationTime + "</br>");
srno += 1;
}
}
public void getdata_3()
{
// int[] myarr = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
int[] myarr = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
var q = from item in myarr
where item.IsEven() // where item.IsOdd() see below
orderby item ascending
select item;
foreach (int i in q)
{
Response.Write(i + "</br>");
}
}
// EXTENSION METHODS IN THE CLASS FILE NAMED "EXTENSIONS",
//public static class Extensions
//{
// public static bool IsOdd(this int value)
// {
// return value % 2 != 0;
// }
// public static bool IsEven(this int value)
// {
// return value % 2 == 0;
// }
//}
public void getdata_4()
{
int[] testarr = new int[] {1,2,3,4,5,6,7,8,9,10};
// int[] testarr1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
var q = from item in testarr
where item % 2 != 0 orderby item descending
select item;
foreach(var val in q)
{
Response.Write(val + "</br>");
}
}
public void getdata_5()
{
// old way of iterating
int[] testarr = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
List<int> mylist = new List<int>();
foreach (int i in testarr)
{
if (i % 2 != 0)
{
mylist.Add(i);
}
}
// mylist = List<int[]> mylist.Sort();
foreach (int i in mylist)
{
Response.Write(i + "</br>");
}
}
public void getdata6()
{
int[] intarr = new int[] {1,2,3,4,5,6,7,8,9,10 };
var q = intarr
.Where(item => item % 2 != 0)
.OrderByDescending(item => item)
.Select(item => item.ToString());
foreach (var val in q)
{
Response.Write(val + "</br>");
}
}
*******************************************************************************
LINQ PRACTISE SNIPPETS 3 WITH UNTYPED DATASET
*******************************************************************************
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
bindgridview();
// createDatatable();
}
}
public void bindgridview()
{
DataTable dt = new DataTable();
dt = createDatatable();
var q = from p in dt.AsEnumerable()
where p.Field<Int32>("ID") >= 10
select new
{
Id = p.Field<Int32>("ID"),
ProductName = p.Field<String>("Name")
};
GridView1.DataSource = q;
GridView1.DataBind();
}
public DataTable createDatatable()
{
DataTable dt = new DataTable("Products");
DataColumn dc;
dc = new DataColumn("ID", typeof(System.Int32));
dt.Columns.Add(dc);
dc = new DataColumn("Name", typeof(System.String));
dt.Columns.Add(dc);
DataRow dr;
for (int i = 1; i <= 20; i++)
{
dr = dt.NewRow();
dr["ID"] = i;
dr["Name"] = "Product-" + i.ToString();
dt.Rows.Add(dr);
}
return dt;
}
}
*******************************************************************************
LINQ PRACTISE SNIPPETS 3 WITH Entity framework .edmx
*******************************************************************************
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
bindCategory();
}
}
protected void ShowProductsOfCategory_Click(object sender, EventArgs e)
{
Int32 id = Convert.ToInt32(ddlCategory.SelectedItem.Value.ToString());
using (testDataTransferEntities ctx = new testDataTransferEntities())
{
var q = from p in ctx.Products
where p.CategoryID == id
select new { p.CategoryID, p.ProductID,p.ProductName, p.UnitPrice,
p.UnitsInStock, p.UnitsOnOrder
};
GridView1.DataSource = q.ToList();
GridView1.DataBind();
}
}
public void bindCategory()
{
DataTable dt = new DataTable();
DataRow dr;
DataColumn dc;
dc = new DataColumn("ID", typeof(string));
dt.Columns.Add(dc);
dc = new DataColumn("CategoryName", typeof(string));
dt.Columns.Add(dc);
using (testDataTransferEntities ctx = new testDataTransferEntities())
{
var cat = from c in ctx.GetAllCategories()
select new
{
c.CategoryID,
c.CategoryName
};
foreach (var ct in cat)
{
dr = dt.NewRow();
dr["ID"] = ct.CategoryID;
dr["CategoryName"] = ct.CategoryName;
dt.Rows.Add(dr);
}
}
if (dt.Rows.Count > 0)
{
ddlCategory.DataSource = dt;
ddlCategory.DataTextField = "CategoryName";
ddlCategory.DataValueField = "ID";
ddlCategory.DataBind();
}
}
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName.ToLower().Equals("edit"))
{
GridViewRow grow = (GridViewRow)((ImageButton)(e.CommandSource)).NamingContainer;
ImageButton imgbtn = (ImageButton)grow.FindControl("imgSelect");
Int32 pid = Convert.ToInt32(imgbtn.CommandArgument);
ViewState["pid"] = pid;
using (testDataTransferEntities ctx = new testDataTransferEntities())
{
var q = from c in ctx.Categories
join p in ctx.Products on c.CategoryID equals p.CategoryID
where p.ProductID == pid
select new
{
c.CategoryID,
c.CategoryName,
p.ProductID,
p.ProductName,
p.UnitPrice,
p.UnitsInStock
};
foreach (var a in q)
{
txtCategory.Text = a.CategoryName;
txtProduct.Text = a.ProductName;
txtUnitPrice.Text = a.UnitPrice.ToString();
}
}
//// THIS IS OK
//var q = from p in ctx.Products
// join c in ctx.Categories on p.CategoryID equals c.CategoryID
// select p.CategoryID + c.CategoryName + p.ProductName + p.UnitPrice;
//using (testDataTransferEntities ctx = new testDataTransferEntities())
//{
// // Category cat =(Category) ctx.Categories;
// var groupJoinQuery2 =
// from category in ctx.Categories
// join prod in ctx.Products on category.CategoryID equals prod.CategoryID into prodGroup
// //orderby category.ca
// select new
// {
// Category = category.CategoryName,
// Products = from prod2 in prodGroup
// orderby prod2.ProductName
// select prod2
// };
//var q = from p in ctx.Products
// join c in ctx.Categories
// on new {p.CategoryID} equals new {c.CategoryID}
// into details
// from d in details
// select new {}
//var q = from p in ctx.Products.Include("Categories")
// select new{
// p.CategoryID, p.ProductID, p.ProductName, p.UnitPrice, p.UnitsInStock, p.UnitsOnOrder
// };
}
}
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
}
protected void btnUpdate_Click(object sender, EventArgs e)
{
//usp_UpdateProduct
Int32 pid = Convert.ToInt32(ViewState["pid"].ToString());
string pname = txtProduct.Text.Trim().ToString();
decimal price = Convert.ToDecimal(txtUnitPrice.Text.Trim().ToString());
using (testDataTransferEntities ctx = new testDataTransferEntities())
{
Int32 intResult = Convert.ToInt32(ctx.updateProduct(pid,pname,price).FirstOrDefault());
if (intResult == 1)
{
ScriptManager.RegisterStartupScript(Page, typeof(Page), "mykey", "alert('Successfully updated!');", true);
}
else
{
ScriptManager.RegisterStartupScript(Page, typeof(Page), "mykey", "alert('Successfully updated!');", true);
}
}
ShowProductsOfCategory_Click(sender,e);
}
protected void btnAddCategory_Click(object sender, EventArgs e)
{
using (testDataTransferEntities ctx = new testDataTransferEntities())
{
Category mycat = new Category {CategoryName= txtCategoryName.Text.Trim().ToString(),Description="testDesc" };
ctx.Categories.AddObject(mycat);
ctx.SaveChanges();
txtCategoryName.Text = "";
}
}
}
*******************************************************************************
LINQ PRACTISE SNIPPETS 4 SAVING DATA USING SP (WITHOUT O/P PARAMETER)
(use select @retVal in the stored procedure)
*******************************************************************************
protected void btnAdd_Click(object sender, EventArgs e)
{
using (testDataTransferEntities ctx = new testDataTransferEntities())
{
//var p = from a in ctx.Products // works ok
// where a.UnitPrice > 18m
// select a;
//GridView1.DataSource = p;
//GridView1.DataBind();
//Category cat = new Category() // works ok without using the stored procedure
//{
// CategoryName = txtCatName.Text.ToString(),
// Description = txtDesc.Text.ToString()
//};
//ctx.Categories.AddObject(cat);
//ctx.SaveChanges();
// ADDING CATEGORY WITH USING STORED PROCEDURE
string catname = txtCatName.Text.ToString();
string catdesc = txtDesc.Text.ToString();
Int32 intresult = Convert.ToInt32(ctx.usp_InsertCategory_New_
_withoutOutPutParameterInSP(catname, catdesc).FirstOrDefault());
if (intresult == 1)
{
ScriptManager.RegisterStartupScript
(Page, typeof(Page), "mykey1", "alert('Success');", true);
}
else if (intresult == -1)
{
ScriptManager.RegisterStartupScript(Page, typeof(Page), "mykey1", "alert('some error');", true);
}
else if (intresult == -2)
{
ScriptManager.RegisterStartupScript(Page, typeof(Page), "mykey1", "alert('Already exists');", true);
}
}
}
protected void btnShowAllCategory_Click(object sender, EventArgs e)
{
using (testDataTransferEntities ctx = new testDataTransferEntities())
{
var q = from c in ctx.Categories
orderby c.CategoryID descending
select c;
GridView1.DataSource = q.ToList();
GridView1.DataBind();
}
}
}
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