Base 62 is used by tinyurl and bit.ly for the abbreviated URLs. It’s a well-understood method for creating “unique”, human-readable IDs. Of course you will have to store the created IDs and check for duplicates on creation to ensure uniqueness. (See code at bottom of answer) Base 62 uniqueness metrics 5 chars in base 62 … Read more
1. There is a UUID pub package: http://pub.dartlang.org/packages/uuid example usage: import ‘package:uuid/uuid.dart’; // Create uuid object var uuid = Uuid(); // Generate a v1 (time-based) id uuid.v1(); // -> ‘6c84fb90-12c4-11e1-840d-7b25c5ee775a’ // Generate a v4 (random) id uuid.v4(); // -> ‘110ec58a-a0f2-4ac4-8393-c866d813b8d1’ // Generate a v5 (namespace-name-sha1-based) id uuid.v5(uuid.NAMESPACE_URL, ‘www.google.com’); // -> ‘c74a196f-f19d-5ea9-bffd-a2742432fc9c’ 2. This src has … Read more
This is all perfectly normal. Microsoft added sequences in SQL Server 2012, finally, i might add and changed the way identity keys are generated. Have a look here for some explanation. If you want to have the old behaviour, you can: use trace flag 272 – this will cause a log record to be generated … Read more
You need to set identity_insert YourTable ON Then delete your row and reinsert it with different identity. Once you have done the insert don’t forget to turn identity_insert off set identity_insert YourTable OFF
The @@identity function returns the last identity created in the same session. The scope_identity() function returns the last identity created in the same session and the same scope. The ident_current(name) returns the last identity created for a specific table or view in any session. The identity() function is not used to get an identity, it’s … Read more
You should not need to query the database directly for the current ApplicationUser. That introduces a new dependency of having an extra context for starters, but going forward the user database tables change (3 times in the past 2 years) but the API is consistent. For example the users table is now called AspNetUsers in … Read more
System.identityHashCode(yourObject) will give the ‘original’ hash code of yourObject as an integer. Uniqueness isn’t necessarily guaranteed. The Sun JVM implementation will give you a value which is related to the original memory address for this object, but that’s an implementation detail and you shouldn’t rely on it. EDIT: Answer modified following Tom’s comment below re. … Read more
Read this very nice article on the subject: Don’t Let Hibernate Steal Your Identity. The conclusion of the article goes like this: Object identity is deceptively hard to implement correctly when objects are persisted to a database. However, the problems stem entirely from allowing objects to exist without an id before they are saved. We … Read more
Make sure that the Key column’s datatype is int and then setting identity manually, as image shows Or just run this code — ID is the name of the [to be] identity column ALTER TABLE [yourTable] DROP COLUMN ID ALTER TABLE [yourTable] ADD ID INT IDENTITY(1,1) the code will run, if ID is not the … Read more
Take a look at this: >>> a = 256 >>> b = 256 >>> id(a) 9987148 >>> id(b) 9987148 >>> a = 257 >>> b = 257 >>> id(a) 11662816 >>> id(b) 11662828 Here’s what I found in the Python 2 documentation, “Plain Integer Objects” (It’s the same for Python 3): The current implementation keeps … Read more