UPDATE statement conflicted with the FOREIGN KEY constraint on Sql Server 2014

Question

Hi guys I have to update a foreign key, on a server sql 2014, but when I run the code below I have the following error, how can fix it?

Error:

Msg 3621, Level 0, State 0. The statement has been terminated. Msg 547, Level 16, State 0. The UPDATE statement conflicted with the FOREIGN KEY constraint "fk_restirizione_idrapportomobile". The conflict occurred in database "db", table "dbo.RapportoMobile", column 'IdRapportoMobile'. (Line 1)

SQL Code:

UPDATE risorsarapportomobile 
SET    risorsarapportomobile.idrapportomobile = 1236 
WHERE  risorsarapportomobile.idrisorseumane IN (SELECT 
       risorseumane.idrisorseumane 
                                                FROM   risorsarapportomobile 
                                                       INNER JOIN risorseumane 
                                                               ON 
       risorseumane.idrisorseumane = 
       risorsarapportomobile.idrisorseumane 
       WHERE  risorsarapportomobile.idrapportomobile IS NULL 
       AND CONVERT(VARCHAR(10), '26-06-2018', 105) = 
           CONVERT(VARCHAR(10), risorseumane.data, 105) 
       AND risorseumane.idcantiere = 158) 

Tables:

Answer 1

Your idRaprortoMobile is 12, not 1236. 1236 is idRapporto. Check what column your foreign key points to, and you'll see it's the issue.

Answer 2

Since you have only one field after SET, and due to the error message, we can deduce that

the value 1236 you want to enter is not present in dbo.RapportoMobile.IdRapportoMobile, which is the target of the foreign key.

Add the value to that column first, then run your update.