Top "Unique-key" questions

A key is a set of attributes that is irreducibly unique and non-nullable within a table.

SQL - Unique Key, Primary Key & Foreign Key

What are the differences between Unique Key, Primary Key and Foreign Key with respect to concept of SQL? How they …

sql foreign-keys primary-key rdbms unique-key
Primary key and unique key in django

I had a custom primary key that need to be set up on a particular data in a model. This …

django primary-key unique-key
Oracle unique constraint and unique index

Could someone clarify what is the purpose of having unique index without unique constraint (Oracle)? For example, create table test22(…

oracle unique-key
How can I catch UniqueKey Violation exceptions with EF6 and SQL Server?

One of my tables have a unique key and when I try to insert a duplicate record it throws an …

c# sql-server exception-handling entity-framework-6 unique-key
make text column as unique key

i want to make a table in MySQL server with mediumtext column as UNIQUE KEY CREATE TABLE `parts` ( `id` int(11) …

mysql sql database unique-key
MySQL: ALTER IGNORE TABLE ADD UNIQUE, what will be truncated?

I have a table with 4 columns: ID, type, owner, description. ID is AUTO_INCREMENT PRIMARY KEY and now I want …

mysql alter-table unique-key
Filter unique values from a JSON

I am using angularjs for my page. I want to filter the values from the JSON object, So that no …

angularjs filter unique unique-key ng-repeat
MySQL - Make a pair of values unique

I have a table with two int values that are IDs. On their own these IDs can show up any …

mysql composite-key unique-key
how to get PC unique id?

What is the PC unique ID? How could we get the PC unqiue ID? Is it about Hard disk or …

vb.net visual-studio-2005 unique-key
Is it bad to use user name as primary key in database design?

I was told by a friend: What unique key do you use? I hope you are not saving the entire …

mysql database-design primary-key unique-key