MySQL query with 2 SELECTs, UNION and LIMIT - how to count all items?

Question

I can't figure out how to count results from my query because I limit the output:

(SELECT "new" as type, name FROM newUsers WHERE name LIKE '%John%')
UNION
(SELECT "old" as type, name FROM oldUsers WHERE name LIKE '%John%')
ORDER BY 1 ASC LIMIT 1, 10

The farthest I got was to do SELECT COUNT(*) ( my query ) as userCount but then I don't get all other fields that were outputted by my query.

Answer 1

( select SQL_CALC_FOUND_ROWS ...)
union
( select ...) // not using SQL_CALC_FOUND_ROWS here
order by ... limit ...;

After getting result from the first query,
you can query again

 select found_rows(); // to get all the rows count

The info from documentation

Answer 2

This would probably answer the letter of what you seem to be asking for, but isn't a very sensible way to formulate the query:

SELECT c.numusers, n.type, n.name
  FROM (SELECT "new" AS type, name  FROM newUsers WHERE name LIKE '%John%') AS n
  JOIN (SELECT COUNT(*) AS numusers FROM newUsers WHERE name LIKE '%John%') AS c
UNION
SELECT c.numusers, o.type, o.name
  FROM (SELECT "old" AS type, name  FROM oldUsers WHERE name LIKE '%John%') AS o
  JOIN (SELECT COUNT(*) AS numusers FROM oldUsers WHERE name LIKE '%John%') AS c
ORDER BY 1 ASC LIMIT 1, 10

The only oddity here is that there is no join condition (neither an ON nor a USING clause) between the two tables. You might need to use a CROSS JOIN instead of an (INNER) JOIN; alternatively, you can introduce a column "new" AS type to the count query, and join ON n.type = c.type . You might then need to add a GROUP BY clause - in most DBMS you would need it, but MySQL may let you get away without it.

However, I think you would do better with two separate queries - one for the type and name as in your question, and the other as:

SELECT COUNT(*) AS numusers, "new" AS type
  FROM newUsers
 WHERE name LIKE '%John%'
 GROUP BY type
UNION
SELECT COUNT(*) AS numusers, "old" AS type
  FROM oldUsers
 WHERE name LIKE '%John%'
 GROUP BY type;

Given that you are using MySQL, you may be able to get away without the GROUP BY clauses in the second query.