MySQL Question - Unique Key Not functioning correctly, or am I misunderstanding?

Question

I\'m trying to create a relation where any of four different parts may be included, but any collection of the same parts should be handled as unique.

Example: An ass

Answer 1

I see that this was asked in 2009. However it is often requested from MySQL: https://bugs.mysql.com/bug.php?id=8173 and https://bugs.mysql.com/bug.php?id=17825 for example. People can click on affects me to try and get attention from MySQL.

Since MySQL 5.7 we can now use the following workaround:

ALTER TABLE test 
ADD generatedLocationID INT AS (ifNull(locationID, 0)) NOT NULL,
ADD generatedWorkgroupID INT AS (ifNull(workgroupID, 0)) NOT NULL,
ADD generatedProgramID INT AS (ifNull(programID, 0)) NOT NULL,
ADD UNIQUE INDEX (companyID, generatedLocationID, generatedWorkgroupID, generatedProgramID);

The generated columns are virtual generated columns, so they have no storage space. When a user inserts (or updates) then the unique index cause the value of the generated columns to be generated on the fly which is a very quick operation.