<html>
<head>
<script language="JavaScript">
function testCtrlKeys(e)
{
//Create an array for all possible keys
var arrCtrlKeys = new Array('a', 'n', 'c', 'x', 'v', 'j');
var key;
var isCtrl;
if(window.event)
{
key = window.event.keyCode; //Valid only for Internet Explorer
if(window.event.ctrlKey)
isCtrl = true;
else
isCtrl = false;
}
else
{
key = e.which; //this is other than IE
if(e.ctrlKey)
isCtrl = true;
else
isCtrl = false;
}
//if ctrl is pressed check if other key is in forbidenKeys array
if(isCtrl)
{
for(i=0; i<arrCtrlKeys .length; i++)
{
//case-insensitive comparation
if(arrCtrlKeys[i].toLowerCase() == String.fromCharCode(key).toLowerCase())
{
alert('You have pressed CTRL + '
+String.fromCharCode(key)
+'.');
return false;
}
}
}
return true;
}
</script>
</head>
<body>
<form method="">
<div>
<h3>Test Key Combinition [Ctrl+A, Ctrl+N, Ctrl+C, Ctrl+X, Ctrl+V,Ctrl+J]</h3>
<input type="text" name="mytext"
onKeyPress="return testCtrlKeys(event);"
onKeyDown="return testCtrlKeys(event);" />
</div>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>Capturing Mouse Events Using JavaScript</title>
</head>
<body>
<div>
<b> Testing with Link Button : </b>
<a href="javascript:void(null)"
onmousedown="return captureButton(event)" onmouseup="return preventOperation(event)"
onclick="return preventOperation(event)" ondblclick="return preventOperation(event)"
oncontextmenu="return preventOperation(event)"
>Click here with various mouse buttons to test</a>
</div>
<br/>
<div>
<b> Testing wuth Submit Button : </b>
<input name=btnG type=submit onmousedown="return captureButton(event)" onmouseup="return preventOperation(event)"
onclick="return preventOperation(event)" ondblclick="return preventOperation(event)"
oncontextmenu="return preventOperation(event)">
</div>
<br/>
<div>
<b> Testing with Input Text : </b>
<input name=btnG type=text onmousedown="return captureButton(event)" onmouseup="return preventOperation(event)"
onclick="return preventOperation(event)" ondblclick="return preventOperation(event)"
oncontextmenu="return preventOperation(event)">
</div>
<script language="Javascript">
function captureButton(event)
{
var button;
if (event.which == null)
button= (event.button < 2) ? "MOUSE BUTTON : LEFT" :
((event.button == 4) ? "MOUSE BUTTON : MIDDLE" : "MOUSE BUTTON : RIGHT");
else
button= (event.which < 2) ? "MOUSE BUTTON : LEFT" :
((event.which == 2) ? "MOUSE BUTTON : MIDDLE" : "MOUSE BUTTON : RIGHT");
alert(button);
preventOperation(event);
}
function preventOperation(event)
{
if (event.preventDefault)
event.preventDefault();
else
event.returnValue= false;
return false;
}
</script>
</body>
</html>
<script runat="server">
SqlConnection myCon = new SqlConnection("Server=localhost;database=HRnPAYROLL;trusted_Connection=true");
SqlCommand myCmd = null;
SqlDataReader myDr = null;
SqlDataAdapter myDa = null;
DataSet myDs = null;
String strOutPut = string.Empty;
protected void Page_Load(object sender, EventArgs e)
{
Getfields_DataReader();
Getfields_DataReader_SchemaOnly();
Getfields_DataSet();
}
/// <summary>
/// Retrieves all filed/column names of DataReader using GetName method without SchemaOnly
/// </summary>
protected void Getfields_DataReader()
{
myCmd = new SqlCommand("Select * from Employees", myCon);
myCon.Open();
myDr = myCmd.ExecuteReader();
//Store total number of Columns
Int32 totCol = myDr.FieldCount; //Fiedl count returns the number of total columns
Response.Write("<div class=\"upperColumn\">");
Response.Write("<h1>Retrieves All Field Names from DataReader using GetName Without SchemaOnly</h1>");
strOutPut = "<table border=\"1\"><tr> <td>Column Name</td> <td>Data Type</td></tr>";
for (Int32 intCol = 0; intCol < totCol; intCol++)
{
strOutPut += "<tr><td>" + myDr.GetName(intCol) + "</td>";
strOutPut += "<td>" + myDr.GetFieldType(intCol) + "</td></tr>";
}
strOutPut += "</table>";
//Write the output
Response.Write("<br/>" + strOutPut + "</Div> <br class=\"clear\" />");
myCon.Close();
}
/// <summary>
/// Retrieves all filed/column names of DataReader using SchemaOnly
/// </summary>
protected void Getfields_DataReader_SchemaOnly()
{
myCmd = new SqlCommand("Select * from HR_MAST_DEPT", myCon);
myCon.Open();
myDr = myCmd.ExecuteReader(CommandBehavior.SchemaOnly);
//Store total number of Columns
Int32 totCol = myDr.FieldCount; //Fiedl count returns the number of total columns
Response.Write("<div class=\"content\"> <div class=\"bottomColumn\">");
Response.Write("<h1>Retrieves All Field Names from DataReader using SchemaOnly</h1>");
strOutPut = "<table border=\"1\"><tr> <td>Column Name</td> <td>Data Type</td></tr>";
for (Int32 intCol = 0; intCol < totCol; intCol++)
{
strOutPut += "<tr><td>" + myDr.GetName(intCol) + "</td>";
strOutPut += "<td>" + myDr.GetFieldType(intCol) + "</td></tr>";
}
strOutPut += "</table>";
//Write the output
Response.Write("<br/> " + strOutPut + "</Div> </Div><br class=\"clear\" />");
myCon.Close();
}
/// <summary>
/// Retrieves all filed/column names of DataSet using ColumnName
/// </summary>
protected void Getfields_DataSet()
{
myDa = new SqlDataAdapter("Select * from Employees", myCon);
myDs = new DataSet();
myDa.Fill(myDs);
Response.Write("<div class=\"content\"> <div class=\"rightColumn\">");
Response.Write("<h1>Retrieves All Field Names from DataSet ColumnName</h1>");
strOutPut = "<table border=\"1\"><tr> <td>Column Name</td> <td>Data Type</td></tr>";
for (Int32 intCol = 0; intCol < myDs.Tables[0].Columns.Count; intCol++)
{
strOutPut += "<tr><td>" + myDs.Tables[0].Columns[intCol].ColumnName + "</td>";
strOutPut += "<td>" + myDs.Tables[0].Columns[intCol].DataType + "</td></tr>";
}
strOutPut += "</table>";
//Write the output
Response.Write("<br/> " + strOutPut + "</Div> </Div>");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<style type="text/css">
.content
{
margin:auto;
width:600px;
background-color:white;
border:Solid 2px orange;
}
html
{
background-color:gray;
font:14px Georgia,Serif,Garamond;
}
h1
{
color:Green;
font-size:18px;
border-bottom:Solid 1px orange;
}
.lbl
{
color:green;
font-weight:bold;
}
.upperColumn
{
margin:auto;
width:500px;
border:Solid 2px orange;
background-color:white;
padding:10px;
}
.bottomColumn
{
margin:auto;
width:700px;
border:Solid 2px orange;
background-color:white;
padding:10px;
}
.leftColumn
{ float:left;
width:300px;
height:150px;
border-right:Solid 1px gray;
background-color:white;
padding:5px;
}
.rightColumn
{ float:left;
height:150px;
border-left:Solid 1px gray;
padding:5px;
}
.clear
{
clear:both;
}
</style>
<title>How to retrieve all field names of datareader</title>
</head>
<body>
<form id="form1" runat="server">
</form>
</body>
</html>
JIT compiler is a crucial component of the .NET framework. The JIT compiler converts IL to machine code, which is then executed. The JIT compiler does not compile the entire code at once because it could hamper the performance of the program. It compiles the code at runtime, at the time it is called. The code that is compiled gets stored until the execution comes to an end. This avoids recompilation of code.
Types of JIT
There following three types of JIT:
Pre-JIT
It compiles whole source code into native code in a single compilation cycle. This is done at the time of deployment of the application
Econo-JIT
It compiles only those methods that are called at runtime. However, these methods are removed when they are not required.
Normal-JIT
It also compiles only those methods which are called at runtime. These methods are compiled the first time they are called, and then they are stored in cache. When the same methods are called again, the compiled code from cache is used for execution
Stored procedure helps to make your work easy. With the help of these you just have to supply some parameters only.
The Code snippet using storedprocedures describes a way to use stored procedures.
Whenever you have to update more than one table or destinations then it must have to sure that the operation done successfully because some time it has been seen that one table updated but due to some error another(s) not. To overcome this problem you have Transactions.
In ADO.Net transactions are initiated by calling BeginTransaction() methods on the database connection object.
Isolation Level(s) | Description |
| ReadCommitted | Its default for SQL Server. It ensures that data written by one transaction will only be accessible in a second transaction after the first transaction commits. |
| ReadUnCommitted | It permits transaction to read data within the database, even data that have not yet been committed by another transaction. |
| RepeatableRead | It extends the ReadCommitted level, ensures that if the same statement issued within the transaction, regardless of other potential updates made to the database, the same data will always be returned. |
| Serializable | It is the most exclusive transaction level, which in effect serializes access to data within the database. With this level, phantom rows can never show up, so a SQ statement issued within a serializable transaction will always retrieve the same data. |
Bellow is the code snippet to show transaction in action:
string myConStr = "server=(local); integrated security=SSPI;database=HRnPAYROLL";
using (SqlConnection myCon = new SqlConnection(myConStr))
{
//Open connection object
myCon.Open();
SqlTransaction nTran = myCon.BeginTransaction();
//some code for work
nTran.Commit();
}