4 ms·

So much of microsoft's documentation is like this nowadays. There's parts of the 'What's new in C# 8.0' that aren't really there, and the provided code samples

So much of microsoft's documentation is like this nowadays. There's parts of the 'What's new in C# 8.0' that aren't really there, and the provided code samples are entirely wrong (i.e. not just one issue, the language literally can't do the feature.) See also the state of most documentation for ASPNETCORE. > BTW if you use the long-existing "update from ...join" syntax which MS released years ago as an extension, be aware it allows you to do stupid things that ansi-standard SQL does not, like repeated unpredictable updates to the same row, in the same single sql statement. I hit that last year in someone else's code. It's broken. Well, what's new. I'm curious if you have an example. I know it's not ANSI standard but I've yet to run into any issues. MERGE on the other hand is a dumpster fire and everyone knows it.

throwaway_pdp09 6y ago
Merge... christ. When I saw the list of fuckups around that my heart sank, it's such a nice statement, if only it worked. I've chosen never to use it (in MSSQL). As for update from, see here https://www.sqlservercentral.com/forums/topic/is-update-from-only-available-in-sql-2005#post-1530797 https://www.sqlservercentral.com/forums/topic/is-update-from... IIRC If you join on unique columns you're safe, but like I said, I found 2 cases of this last year in some code where the cols joined were not were not unique. That meant the output was, quite simply, junk.
- csharptwdec19 6y ago
  Ahhhhh... I've never run into that issue, but I can see how it would be frustrating. I guess I've always just taken those risks from a cross-join for granted. Possibly because I cut my teeth on Oracle 10g, and when you are having to consistently write update statements the ANSI way you get in the habit of making sure that you'll only get a single record per row. Unless I know the table in FROM is going to be 1-1 I'll make sure to consider the right way to put a TOP 1 in (usually null merges)

throwaway_pdp09 6y ago

Merge... christ. When I saw the list of fuckups around that my heart sank, it's such a nice statement, if only it worked. I've chosen never to use it (in MSSQL). As for update from, see here https://www.sqlservercentral.com/forums/topic/is-update-from-only-available-in-sql-2005#post-1530797 https://www.sqlservercentral.com/forums/topic/is-update-from... IIRC If you join on unique columns you're safe, but like I said, I found 2 cases of this last year in some code where the cols joined were not were not unique. That meant the output was, quite simply, junk.

csharptwdec19 6y ago
Ahhhhh... I've never run into that issue, but I can see how it would be frustrating. I guess I've always just taken those risks from a cross-join for granted. Possibly because I cut my teeth on Oracle 10g, and when you are having to consistently write update statements the ANSI way you get in the habit of making sure that you'll only get a single record per row. Unless I know the table in FROM is going to be 1-1 I'll make sure to consider the right way to put a TOP 1 in (usually null merges)