Counting multiple LIKE results from multiple columns?

Question

I'm trying to build a query to look at tickets in our help desk system. I would like to search for a few keywords, ie "email" in either the subject or description fields, and return a count of each keyword. Below is a sample table. There is a categories row as well, however it wasn't well maintained so most of the fields are empty.

  ID |       Subject         | Description
-----+-------------------------------------
   1 | hellloooo             | can't send email
   2 | email down?           | can't get to intranet
   3 | Phone trouble         | can't check voicemail
   4 | Using my phone        | I don't know how
   5 | Need new mouse        | please replace
   6 | Mouse acting funny    | n/a
   7 | Intranet won't Load   | what's this plug do?
   8 | not getting voicemail | why not?

And I would like to return something like

Category   |   # of tickets
---------------------------
Email      |   3
Phone      |   2
Intranet   |   2

What would the easiest way to do this be?

Answer 1

You did not specify the RDBMS, but the following will work in SQL Server

;with cte as
(
  select 'Email' Category
  UNION ALL
  select 'Phone'
  UNION ALL
  select 'Intranet'
)
select category, count(*)
from cte c
inner join tickets t
  on t.subject like '%' + c.category + '%'
  or t.description like '%' + c.category + '%'
group by category

See SQL Fiddle with Demo

If you have a longer list of categories that you want to query on, then you might want to consider storing it in a separate table and joining on the table.

Edit for Sqlite, there is not CTE so you can do my example the following way (Updated to use the correct syntax to concatenate in SQLite):

select category, count(*)
from 
(
  select 'Email' Category
  UNION ALL
  select 'Phone'
  UNION ALL
  select 'Intranet'
) c
inner join tickets t
  on t.subject like '%' || c.category || '%'
  or t.description like '%' || c.category || '%'
group by category

See SQL Fiddle with Demo

Answer 2

Using Microsoft SQL Server, I might do something like this:

DECLARE @CategoryList TABLE (Category VARCHAR(MAX))

INSERT INTO @CategoryList VALUES ('Email')
INSERT INTO @CategoryList VALUES ('Phone')
INSERT INTO @CategoryList VALUES ('Intranet')

SELECT Category, COUNT(*) AS NumberOfTickets
FROM Tickets
INNER JOIN @CategoryList CategoryList ON Tickets.Subject LIKE '%' + CategoryList.Category + '%' OR Tickets.Description LIKE '%' + CategoryList.Category + '%'
GROUP BY Category