Tables without Primary Key in Database

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Some times you are analyzing the database to check which tables don't have primary keys then  in that case follwing query will help you to find out the tables:

Below SQL will give you the list of table in you Database not having Primary Keys.

SELECT SCHEMA_NAME(schema_id) AS SchemaName,name AS TableName

FROM sys.tables

WHERE OBJECTPROPERTY(OBJECT_ID,'TableHasPrimaryKey') = 0

ORDER BY SchemaName, TableName;

Happy Coding!! 

Custom errors in web.config

Some times after hosting web application on the server, we get unexpected error. But we did not get the detailed message for the unexpected error or if we added defaultredirect="error.htm".

<customErrors defaultRedirect="error.htm" mode="On" />

  how can we get detailed message for the unexpected error. Unexpected error may occur on remote or on local server. We can find out exact error message by doing some changes in web.config. Just change Custom error  mode to off.

<customErrors defaultRedirect="error.htm" mode="Off" />

There are three error modes in which an ASP.NET application can work:

1) Off Mode
2) On Mode
3) RemoteOnly Mode

The Error mode attribute determines whether or not an ASP.NET error message is displayed. By default, the mode value is set to "RemoteOnly".

Off Mode

When the error attribute is set to "Off", ASP.NET uses its default error page for both local and remote users in case of an error.

On Mode

In case of "On" Mode, ASP.NET uses user-defined custom error page instead of its default error page for both local and remote users. If a custom error page is not specified, ASP.NET shows the error page describing how to enable remote viewing of errors.

RemoteOnly

ASP.NET error page is shown only to local users. Remote requests will first check the configuration settings for the custom error page or finally show an IIS error. 

Happy Coding!!

Grid view Column- Apply Word wrap to work in all browser

Sometimes in gridview we have a column which has too much information so it is not shown properly on page.

We can achieve with the help of CSS.

.word_wrap
{
    white-space: pre; /* CSS 2.0 */
    white-space: pre-wrap; /* CSS 2.1 */
    white-space: pre-line; /* CSS 3.0 */
    white-space: -pre-wrap; /* Opera 4-6 */
    white-space: -o-pre-wrap; /* Opera 7 */
    white-space: -moz-pre-wrap; /* Mozilla */
    white-space: -hp-pre-wrap; /* HP Printers */
    word-wrap: break-word; /* IE 5+ */
}

We have defined a css class, and we can assign this cssclass to column which has too much information.

<asp:TemplateField HeaderText="Name On Document" meta:resourcekey="HeaderText_NameOnResource1">
    <HeaderStyle Width="100px" Font-Bold="true" />
        <ItemTemplate>
            <div style="word-wrap: break-word; width: 100px;">
                 <%# Eval("NameOnDocument")%>
            </div>
        </ItemTemplate>
        <ItemStyle Width="100px" CssClass="word_wrap" Wrap="true" />
</asp:TemplateField>

Happy Coding!!

Encrypt connection string in web.config file

This time we have written a generalize function which will encrypt an decrypt connection strings.

Following code snippet will help to encrypt connection string in web.config file.

  protected void encryptConfi(bool bencrypt)
        {
            string webconfigfilepath = "~/";
            Configuration config = WebConfigurationManager.OpenWebConfiguration(webconfigfilepath);
            ConfigurationSection configsec = config.GetSection("connectionStrings");
            if (bencrypt)
            {
                configsec.SectionInformation.ProtectSection("DataProtectionConfigurationProvider");
            }
            else
            {
                configsec.SectionInformation.UnprotectSection();
            }
            config.Save();
        }

Happy Coding!!

The Difference Between “Add Web Reference” and “Add Service Reference”

I was playing around with building a simple WCF ASP.NET client in Visual Studio 2008 and wanted to make a reference to my WCF service (that used basicHttpBinding).

I have built plenty of ASMX web services in the past so simply selected “Add Web Reference”, pointed to my .svc file hosted in IIS– everything worked as expected.

Then I checked the “Add Service Reference” menu option and thought – why this option is given?
In interview sometimes this question will be asked to check your understanding of web services.

Add Web Reference

It is a wrapper over wsdl.exe and can be used to create proxies for .NET 1.1 or 2.0 clients. Of course this means when you are pointing to a WCF service you have to be pointing to an endpoint that uses basicHttpBinding.

Add Service Reference 

It is a wrapper over svcutil.exe and also creates clients proxies (and additionally web.config entries). These proxies, however, can only be consumed by .NET 3.0+ clients.

Happy Coding!!

Download File in Asp.net

Following is a snippet required to download a file


    private void StartDownloadFile(string attachmentPath)
        {
            FileInfo file = new FileInfo(attachmentPath);
            Response.Clear();
            Response.ClearHeaders();
            Response.ClearContent();
            Response.AppendHeader("Content-Disposition", "attachment; filename = " + file.Name);
            Response.AppendHeader("Content-Length", file.Length.ToString());
            Response.ContentType = "application/download";
            Response.WriteFile(file.FullName);
            Response.Flush();
            Response.Close();
            Response.End();
        }

This is generalize function, you need to pass path of filename. With the help of above code snippet browser will popup download box where you need to give the path.

Happy Coding!!

hyperlink in template column gridview

following snippet is useful to insert hyperlink template column in grdview 

    <asp:TemplateField  HeaderText="User name">
                <ItemTemplate>
                    <asp:HyperLink runat="server" ID="lnkRedirect"  NavigateUrl='<%# String.Format("~/UserDetails.aspx?username={0}",Container.DataItem) %>' Text='<%# Container.DataItem %>'></asp:HyperLink>
                </ItemTemplate>
            </asp:TemplateField>

if you are binding arraylist to gridview & grdview contains template column then in controls text property use Text='<%# Container.DataItem %>' instead of Text='<%# ColumnName %>' because columnName is not available in arraylist

Happy Coding!!