Mockup code for my problem:
SELECT Id FROM Tags WHERE TagName IN '<osx><keyboard><security><screen-lock>'
The problem in detail
I am trying to get tags used in 2011 from apple.stackexchange data. (this query)
As you can see, tags in tag changes are stored as plain text in the Text
field.
<tag1><tag2><tag3>
<osx><keyboard><security><screen-lock>
How can I create a unique list of the tags, to look them up in the Tags
table, instead of this hardcoded version:
SELECT * FROM Tags
WHERE TagName = 'osx'
OR TagName = 'keyboard'
OR TagName = 'security'
Here is a interactive example.
Stackexchange uses T-SQL, my local copy is running under postgresql using Postgres app version 9.4.5.0.