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The Access-Control-Allow-Origin Header Explained – With a CORS Example Often times when calling an API, you may see an error in your console that looks like this: Access to fetch at 'http://somesite.com' from origin 'http://yoursite.com' has been blocked by CORS policy: The 'Access-Control-Allow-Origin' header has a value that is not equal to the supplied origin Add following in <system.webServer> <httpProtocol> <customHeaders> <add name="Access-Control-Allow-Methods" value="*" /> <add name="Access-Control-Allow-Origin" value="*" /> <add name="Access-Control-Allow-Headers" value="*" /> </customHeaders> </system.webServer> After adding the above code in web.config, received the following error in response. .... Has been blocked by CORS policy: Response to preflight request doesn’t pass access control check:

In this post I will show you how you can easily calculate time difference between two dates in seconds, minutes, hours, days, and even weeks, months and years in SQL. This functionality can be used in notifications, emails, blog post etc The key of this calculation is in Modulo operator, %. It returns the remainder (NOT the result!) of one number divided by another! CREATE FUNCTION [dbo].[FN_GetTimeDifference] (@FromDate DATETIME, @ToDate DATETIME) RETURNS NVARCHAR(50) AS BEGIN DECLARE @Result NVARCHAR(50) SELECT @Result = CASE WHEN DATEDIFF(second, @FromDate, @ToDate) / 60 / 60 / 24 / 7 > 0 THEN CAST(DATEDIFF(second, @FromDate, @ToDate) / 60 / 60 / 24 / 7 AS NVARCHAR(50)) + ' weeks ago' WHEN DATEDIFF(second, @FromDate, @ToDate) / 60 / 60 / 24 % 7 > 0 THEN CAST(DATEDIFF(second, @FromDate, @ToDate) / 60 / 60 / 24 % 7 AS NVARCHAR(50)) + ' days ago' WHEN DATEDIFF(second, @FromDate, @ToDate) / 60 / 60 % 24 > 0 THEN CAS

Working with ASP.NET Web API, the most unexpected thing is the limited support of POST data values to simple ApiController methods. When a parameter has [FromBody], Web API uses the Content-Type header to select a formatter. At most one parameter is allowed to read from the message body. The reason for this rule is that the request body might be stored in a non-buffered stream that can only be read once. A simple principle, you can send any content in HTTP request, it only need to be serializable into a string. So, it could be multiple JSON object. In this example, the content type is "application/json" and the request body is a raw JSON string (not a JSON object). Here I found a workaround to pass multiple complex objects (using the above principle) from jquery to a WEB API using JObject , and then cast back to your required specific object type in api controller. This objects provides a concrete type specifically designed for working with JSON. var customer = { &quo

If you try to invoke a user-defined function (UDF) through a linked server in SQL Server by using a "four-part naming" convention (server.database.dbo.Function), you may receive error message.  The reason is User-defined function calls inside a four-part linked server query are not supported in SQL Server. Thats why error message indicates that the syntax of a Transact-SQL statement is incorrect.  To work around this problem, use the Openquery function instead of the four-part naming convention. For example, instead of the following query Select * from Linked_Server.database.dbo.Function(10) run a query with the Openquery function: Select * from Openquery(Linked_Server,'select database.dbo.Function(10)') If the user-defined function takes variable or scalar parameters, you can use the sp_executesql stored procedure to avoid this behavior.  For example: exec Linked_Server.database.dbo.sp_executesql N'SELECT database.dbo.Function(@input)',N'@input

A new addition to the DELETE command in SQL Server 2005 is the TOP statement. The DELETE TOP does the same thing as a SELECT TOP WHERE only the TOP number of rows are deleted. This can be very helpful when there are duplicate rows of data present. DELETE TOP (1) FROM Sales.Customer WHERE CustomerID = 1 This would delete one of the duplicate rows for Customer number 1 Suppose somehow the whole customer table got duplicated. I duplicated the Sales.Customer table into a tmpCustomer table. SELECT Top 1 CustomerID, COUNT(CustomerID) AS Cnt FROM tmpCustomer GROUP BY CustomerID HAVING COUNT(CustomerID) > 1 WHILE @@RowCount > 0 BEGIN DELETE Top (1) FROM tmpCustomer WHERE CustomerID = (SELECT Top (1) CustomerID FROM tmpCustomer GROUP BY CustomerID HAVING COUNT(CustomerID) > 1) END While this worked just fine, it ran about 4 minutes for 38K rows. Let's try the dreaded CURSOR.