The SQL Server (Transact-SQL) UPDATE statement is used to update existing records in a table in a SQL Server database.There are 3 syntaxes for the UPDATE statement depending on whether you are performing a traditional update or updating one table with data from another table.

updating multiple columns in sql server 2016-63updating multiple columns in sql server 2016-79

This returns a bit pattern that indicates which columns were inserted or updated.

IF UPDATE returns the TRUE value in INSERT actions because the columns have either explicit values or implicit (NULL) values inserted.

I've searched everywhere but I can't seem to make it work or understand why the join is behaving like this and right now I am not able to ask anyone so just trying my luck here. I've finally manage to track down the issue and sadly(frustratingly) its just a null value in some rows in the entire table which prevented the JOIN to function properly.

So here's the issue: tbl Old Access User Srv Perm Log Dt Tm ------------------------------------------------ Test Nm1 Srv1 Perm1 2016-11-20 .000 Test Nm1 Srv2 Perm2 2016-12-30 .000 Test Nm1 Srv1 Perm3 2016-05-30 .000 UPDATE [tbl Old Access] SET [Log Dt Tm] = [tmp].[Log Dt Tm] FROM tbl Old Accessas tmp JOIN ( SELECT [user], Srv, [Perm] from [tbl New Access] INTERSECT SELECT [user], Srv, [Perm] from [tbl Old Access] ) as drv ON tmp.[User] = drv.[User] WHERE tmp.[User] = drv.[User] AND tmp.[Srv] = drv.[Srv] I have tried multiple join condition and even multiple where condition to only update those 2 rows which correspond to ones that needs update in their Log Dt Tm column in the tbl Old Access table.

Personally, I prefer using aliases throughout like I did here: stackoverflow.com/a/982947/27535 If you need to re-type this several times, you can do like I did once.

Get your columns` names into rows in excel sheet (write down at the end of each column name (=) which is easy in notepad ) on the right side make a column to copy and paste your value that will correspond to the new entries at each column.

However, ALTER TABLE is an offline operation which requires more memory temporarily.

The database application can continue to run and any operation that is accessing the table is blocked until the alteration process is completed.

also, there are mitigating methods in client tools (eg generation UPDATE statements) or by using ORMs Agree re.