T-SQL Error: An aggregate may not appear in the set list of an update statement

A reporting project contains a table with the product summary, the table has a lot of KPIs and specifically the "Last Sale Date" of a product.
According to the company rules, a product is sold when it is paid.
The following T-SQL code (shown here very simplified) can be used to update that column:

UPDATE Product
SET LastSalesDate = MAX(Orders.PaymentDate)
FROM Product
    INNER JOIN Orders ON (Orders.ProductID = Product.ProductID)

After executing the statement in Sql Server the following error occurs:

Msg 157, Level 15, State 1, Line 2
An aggregate may not appear in the set list of an UPDATE statement.

The error indicates that a column of a table is being updated applying an aggregate function directly.
The solution is to rewrite the query, using for example a sub-query.
Example:

UPDATE Product
SET LastSalesDate = LastSaleDates.PaymentDate
FROM Product
    INNER JOIN 
    (
        SELECT MAX(Orders.PaymentDate) AS PaymentDate
            ,Orders.ProductID
        FROM Orders
        GROUP BY Orders.ProductID
    ) LastSaleDates ON (LastSaleDates.ProductID = Product.ProductID)

Another possible solution is to use a Common Table Expression (CTE).

;WITH [LastSaleDates] AS
(
    SELECT MAX(Orders.PaymentDate) AS PaymentDate
            ,Orders.ProductID
    FROM Orders
    GROUP BY Orders.ProductID 
)

UPDATE Product
SET LastSalesDate = LastSaleDates.PaymentDate
FROM Product
    INNER JOIN LastSaleDates ON (LastSaleDates.ProductID = Product.ProductID)

How to start SQL Agent job from Another server

A common scenario, when managing a server farm, is to have to sync the SQL Agent jobs in several servers.

You may want to start a job on a second server (SQL02) when a job completes on a primary server (SQL01).

The SQL02 may be a reporting or staging sever, and the SQL01 may be the transnational server.

Sql Server has a T-SQL statement - sp_start_job - to start a job on the server where it is executed.

From the Microsoft Documentation, sp_start_job has the following parameters:

sp_start_job
{[@job_name =] 'job_name' | [@job_id =] job_id }
[ , [@error_flag =] error_flag]
[ , [@server_name =] 'server_name']
[ , [@step_name =] 'step_name']
[ , [@output_flag =] output_flag]

The @server_name parameter is relative to the server where it is executed.
If the parameter supported executing a job from another server it would be great, but no such luck!!!v

The solution is to set a SQL02 as a linked server, this allow that Sql would recognize the remote server as being local.

To configure a linked server on Sql 2014 (It may change from Sql Sever version to Sql Sever Version), follow the next steps:
1) Open Sql Server Management Studio (SSMS)
2) Expand the SQL01 node name
3) Expand "Server Objects"
4) Press the right mouse button on the ""Server Objects"
Example:


5) Write the Linked Server Name: SQL02 in this example
6) Set the server type to SQL Server
7) In Security set the your security settings
In this example the Local login is "sa" and the "Impersonate" checkbox is active. Also the "For a login not defined in the list above, connection will:" option is set to "Be made using this security context", defining the Remote login and password.
Example:


8) On "Server Options" allow "RPC Out"
Example:


9) Press OK and if the everithing is correctly defined the linked server is configured


After configuring the linked server the job can be started on the SQL02 from the SQL01.

To test open a query window on SSMS in the SQL01 server and execute the SP to start the job:

EXEC [SQL02].[msdb].[dbo].[sp_start_job] @job_name = N'MyJob';

Where "MyJob" is the name of the job to start on SQL02

Note that the job is started, but the sp_start_job does not wait for the job "MyJob" to complete the execution.

High CPU usage in Visual Studio 2017

Visual studio 2017 has a High CPU usage after using it for some time.

The issue is very annoying, since the work computer starts to get very slow and unresponsive.

I fixed my problem by performing the following steps:

1. Close all the visual studio open instances
2. Delete all the .suo files from the visual studio solutions folders
3. Remove all the .vs hidden directories from the visual studio solutions folders

Use this solution with caution, so you only delete the referred files or folders.