Top "Unique-index" questions

Unique-index is an index that sets one or multiple fields to be unique in a data entity

Hibernate throws unique constraint violation exception while updating field part of unique key

Below is the use case: I have a unique index defined on 3 columns say A,B,C. Assume the values …

java hibernate unique-constraint unique-index
Rails uniqueness constraint and matching db unique index for null column

I have the following in my migration file def self.up create_table :payment_agreements do |t| t.boolean :automatic, :…

ruby-on-rails migration unique-index validates-uniqueness-of
cakephp isUnique for 2 fields?

I have a registration form in which users can fill in two email address (email1 & email2). Marketing's requirement is …

cakephp unique-index cakephp-model
Check whether a field has the property `UNIQUE` in mysql and PHP

How can I check whether a field from a table is set as UNIQUE? For example I have a table …

php mysql indexing unique-index
MySQL Views in Navicat - How to define 'primary key'?

Often when I define a View in Navicat I receive the following message: xxx does not have a primary key. …

mysql views primary-key unique-index navicat
Is there any way to make a UNIQUE index case insensitive in Mysql 5.1.x ?

If so - What must change in this table ? CREATE TABLE contestants ( idContestants int(10) unsigned NOT NULL AUTO_INCREMENT, idEvent …

mysql unique-index
MySQL Make a combination of columns unique

I have a table that stores comments users make about images on the site. The table is structured with four …

mysql unique-index
How can I constrain multiple columns to prevent duplicates, but ignore null values?

Here's a little experiment I ran in an Oracle database (10g). Aside from (Oracle's) implementation convenience, I can't figure out …

oracle null nullable constraints unique-index
How to partition MySQL table by column that is not in the unique index

Let's have a simple table of products. Each produch has its unique ID and category. Users often search by category …

mysql partitioning unique-index
Should I specify both INDEX and UNIQUE INDEX?

On one of my PostgreSQL tables, I have a set of two fields that will be defined as being unique …

postgresql indexing unique-constraint unique-index