Sunday 21 July 2013

JQuery UI autocomplete textbox with database in asp.net


This is the function declaration of JSON format we are using this JSON function to call web methods using JQuery $.ajax() whenever we need to make Ajax call with JQuery then we will use JSON functions like as we mentioned in above format. Here typeContentType and dataType are same for all functions only urldata and success functions will vary based on our requirement.

url: This is the path of our Webmethods

data: we will pass parameters using this parameter if no parameters then we need to use data: "{}"

success: Once our web method execution completed then success function will execute and return username matching’s

(Note: JSON is a case sensitive please be careful before write JSON format of data)

Now open code behind file and add following namespaces


<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>AutoComplete Box with jQuery</title>
<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/themes/base/jquery-ui.css"rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/jquery-ui.min.js"></script> 
<script type="text/javascript">
$(document).ready(function() {
SearchText();
});
function SearchText() {
$(".autosuggest").autocomplete({
source: function(request, response) {
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "Default.aspx/GetAutoCompleteData",
data: "{'username':'" + document.getElementById('txtSearch').value + "'}",
dataType: "json",
success: function(data) {
response(data.d);
},
error: function(result) {
alert("Error");
}
});
}
});
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div class="demo">
<div class="ui-widget">
<label for="tbAuto">Enter UserName: </label>
<input type="text" id="txtSearch" class="autosuggest" />
</div>
</form>
</body>
</html>

protected void Page_Load(object sender, EventArgs e)
{

}
[WebMethod]

public static List<string> GetAutoCompleteData(string username)
{
List<string> result = new List<string>();
using (SqlConnection con = new SqlConnection("Data Source=SREENIVAS-PC\\SQLEXPRESS;Initial Catalog=Users;User ID=sa;Integrated Security=true"))
{
using (SqlCommand cmd = new SqlCommand("select DISTINCT UserName from UserInformation where UserName LIKE '%'+@SearchText+'%'", con))
{
con.Open();
cmd.Parameters.AddWithValue("@SearchText", username);
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
result.Add(dr["UserName"].ToString());
}
return result;
}
}
}

Diff between DataReader and DataSet and DataAdapter in C#

DataReader

DataReader is used to read the data from database and it is a read and forward only connection oriented architecture during fetch the data from database. DataReader is used to iterate through resultset that came from server and it will read one record at a time because of that memory consumption will be less and it will fetch the data very fast when compared with dataset. Generally we will use Execute Reader object to bind data to datareader.

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Example of ExecuteReader in asp.net</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<b>Bind Gridview with ExecuteReader command object Data</b><br /><br />
<asp:GridView ID="gvUserInfo" runat="server">
<HeaderStyle BackColor="#df5015" Font-Bold="true" ForeColor="White"/>
</asp:GridView>
</div>
</form>
</body>
</html>
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGridview();
}
}

// This method is used to bind gridview from database
protected void BindGridview()
{
using (SqlConnection con = new SqlConnection("Data Source=SREENIVAS-PC\\SQLEXPRESS;Initial Catalog=Users;User ID=sa;Integrated Security=true"))
{
con.Open();
SqlCommand cmd = new SqlCommand("Select UserName,LastName,Location FROM UserInformation", con);
SqlDataReader dr = cmd.ExecuteReader();
gvUserInfo.DataSource = dr;
gvUserInfo.DataBind();
con.Close();
}
}

DataSet

DataSet is a disconnected orient architecture that means there is no need of active connections during work with datasets and it is a collection of DataTables and relations between tables. It is used to hold multiple tables with data. You can select data form tables, create views based on table and ask child rows over relations. Also DataSet provides you with rich features like saving data as XML and loading XML data.


// This method is used to bind gridview from database
protected void BindGridview()
{
SqlConnection con = new SqlConnection("Data Source=SREENIVAS-PC\\SQLEXPRESS;Initial Catalog=Users;User ID=sa;Integrated Security=true");
con.Open();
SqlCommand cmd = new SqlCommand("select UserName,LastName,Location from UserInformation", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
gvUserInfo.DataSource = ds;
gvUserInfo.DataBind();
}


DataAdapter

DataAdapter will acts as a Bridge between DataSet and database. This dataadapter object is used to read the data from database and bind that data to dataset. Dataadapter is a disconnected oriented architecture. Check below sample code to see how to use DataAdapter in code
// This method is used to bind gridview from database
protected void BindGridview()
{
SqlConnection con = new SqlConnection("Data Source=SREENIVAS-PC\\SQLEXPRESS;Initial Catalog=Users;User ID=sa;Integrated Security=true");
con.Open();
SqlCommand cmd = new SqlCommand("select UserName,LastName,Location from UserInformation", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
gvUserInfo.DataSource = ds;
gvUserInfo.DataBind();
}