Top "Unique" questions

Find index where elements change value numpy

Suppose I have >>> v array([1, 1, 1, 1, 1, 2, 2, 2, 3, 4, 3, 4, 3, 4, 3, 4, 5, 5, 5]) Is there an efficient numpy way to find each index where the …

python numpy indexing unique

Generate unique 10 chars alphanumeric hashes in MySQL

I have a simple table with field called "hash" VARCHAR 10 UNIQUE FIELD Now I would like to run a query …

mysql unique dynamically-generated hash

Composite PRIMARY KEY enforces NOT NULL constraints on involved columns

This is one strange, unwanted behavior I encountered in Postgres: When I create a Postgres table with composite primary keys, …

postgresql database-design null unique primary-key

Sqlite insert into with unique names, getting id

I have a list of strings to insert into a db. They MUST be unique. When i insert i would …

sqlite unique identity auto-generate

creating unique page title slugs php

I have a function for creating unique slug for a page title. It checks if the slug is available in …

php mysql unique slug

MySQL generated UID

I am coding a messaging system and I don't want to have short IDs shown, is there any way that …

mysql unique uid

How to get generated ID after I inserted into a new data record in database using Spring JDBCTemplate?

I got a very common question when I was using Spring JDBCTemplate, I want to get the ID value after …

database spring unique jdbctemplate persistent

Conditional unique constraint with multiple fields in oracle db

I have this table: XPTO_TABLE (id, obj_x, date_x, type_x, status_x) I wanna create a unique …

sql oracle conditional unique unique-constraint

Generating a unique ID in PHP

I'm trying to generate a unique ID in php in order to store user-uploaded content on a FS without conflicts. …

php guid unique uuid identifier

How can I remove all duplicates so that NONE are left in a data frame?

There is a similar question for PHP, but I'm working with R and am unable to translate the solution to …

r duplicates unique r-faq