October 16, 2014 at 2:25 am
I've read in a few places that when a constraint name is unspecified the system generates the name randomly, but there's clearly more to this. I mean the hex-looking bit at the end.
For example, when I run this:
CREATE DATABASE TestTheory
GO
USE TestTheory
GO
CREATE TABLE Theory (
Id int identity(1,1) primary key,
Data varchar(20),
LogDate datetime default getdate()
)
On my SQL 2008 R2 laptop the primary key is always PK__Theory__3214EC077F60ED59 and the default constraint is always DF__Theory__LogDate__014935CB - not a different random value each time. Not a major issue as if it's a problem we can simply name the objects - but anybody know what's going on here?
October 16, 2014 at 4:18 am
It must be a hash of some kind based on the server. I got different values than you did. And, if I dropped the table and recreated it, I got different values again.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning
October 16, 2014 at 7:15 am
That's true, if I drop the database and re-run that script the same values come back, if I drop the table different values are used. But those second values are also repeated following dropping the database, so there's a sequence. Definitely not random!
October 16, 2014 at 8:03 am
Random or not, they're ugly to read.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning
October 16, 2014 at 12:21 pm
I admit, I name all constraints myself, including DEFAULTs, even though for DEFAULTs that may be deprecated.
CREATE TABLE Theory (
Id int identity(1,1) CONSTRAINT Theory__PK primary key,
Data varchar(20),
LogDate datetime CONSTRAINT Theory__DF_LogDate default getdate()
)
SQL DBA,SQL Server MVP(07, 08, 09) A socialist is someone who will give you the shirt off *someone else's* back.
Viewing 5 posts - 1 through 4 (of 4 total)
You must be logged in to reply to this topic. Login to reply