Update datetime field by blank in datatable

      Catalogcl oCatalogcl = new Catalogcl();
      DataTable dtModetare = oCatalogcl.Moderate();
      dtModetare.Rows[0]["dt_moderate"] = DBNull.Value;
      DataTable dt = dtModetare;

Verbatim String

A verbatim string is one that does not need to be escaped, like a filename:

string myFileName = "C:\\myfolder\\myfile.txt";

would be

string myFileName = @"C:\myfolder\myfile.txt";

The @ symbol means to read that string literally, and don't interpret control characters otherwise.

Regular Expression

https://www.c-sharpcorner.com/UploadFile/955025/regular-expression-in-C-Sharp/
https://www.c-sharpcorner.com/UploadFile/955025/regular-expression-in-C-Sharp/

https://regex101.com/

Enable/Disable SSL in IIS

Can use Nartac's IIS Crypto tool
Use url https://www.nartac.com/Products/IISCrypto to download Crypto tool.

https://www.sslshopper.com/article-how-to-disable-ssl-2.0-in-iis-7.html
https://www.digicert.com/ssl-support/iis-disabling-ssl-v3.htm

SQL Linked Servers

When you are setting up a linked server, register the connection information and data source information with SQL Server. After registered, that data source can be referred to with a single logical name.

You can use stored procedures and catalog views to manage linked server definitions:

Create a linked server definition by running sp_addlinkedserver.

View information about the linked servers defined in a specific instance of SQL Server by running a query against the sys.servers system catalog views.



Delete a linked server definition by running sp_dropserver. You can also use this stored procedure to remove a remote server.


You can also define linked servers by using SQL Server Management Studio. In the Object Explorer, right-click Server Objects, select New, and select Linked Server. You can delete a linked server definition by right-clicking the linked server name and selecting Delete.

When you execute a distributed query against a linked server, include a fully qualified, four-part table name for each data source to query. This four-part name should be in the form linked_server_name.catalog.schema.object_name.

Url:

https://www.c-sharpcorner.com/UploadFile/suthish_nair/linked-servers-in-sql-server-2008/
https://docs.microsoft.com/en-us/sql/relational-databases/linked-servers/linked-servers-database-engine?view=sql-server-2017
https://docs.microsoft.com/en-us/sql/relational-databases/linked-servers/create-linked-servers-sql-server-database-engine?view=sql-server-2017
https://www.sqlshack.com/how-to-create-and-configure-a-linked-server-in-sql-server-management-studio/

task-scheduler-run-1-tasks-4-times-a-day

It looks like you can add mulitple triggers for a task setting a different time for each trigger. Go back to your task, right click and pick properties. On the "Triggers" tab you can add more tirggers.

URL"

https://stackoverflow.com/questions/6653430/task-scheduler-run-1-tasks-4-times-a-day

Run the task scheduler once a day but not hourly intervals

https://stackoverflow.com/questions/50172709/run-the-task-scheduler-once-a-day-but-not-hourly-intervals

Windows button + R then type taskschd.msc

from the right top side choose, create task.

from top menu choose trigger.

make the settings as below screenshot. trigger settings