来自多个表的结果MySQL

Question

Two tables

Table 1 - customer table

user_id      Name
1            first
2            Second

Table 2 - customer_activity table

user_id      type
1            downloaded_software
1            filled_download_form
2            downloaded_software
2            filled_download_form
2            purchased

Goal - To select all the customers who have downloaded_software, filled_download_form and purchased.

My Query

    SELECT SQL_CALC_FOUND_ROWS DISTINCT(c.user_id) 
      FROM customer AS c 
INNER JOIN customer_activity AS ca ON ca.user_id = c.user_id 
     WHERE ca.type IN('downloaded_software','filled_download_form','purchased') 
  ORDER BY c.user_id asc 
     LIMIT 0, 100

Result

1
2

Desired Result

2

EDIT: Comments summary:

Answer for this question is below but a possible good scenario would be to exclude some items from the list. For example, if I want to do a search for customers who have downloaded_software, filled_software_form but not purchased.

This was answered by @Serpiton in this fiddle in the comments.

Answer 1

You could group by user_id and count the distinct values of type . Since the WHERE restricts the values to only 3 possible, the count of distinct values should be 3 if all are found;

SELECT SQL_CALC_FOUND_ROWS c.user_id 
FROM customer AS c 
JOIN customer_activity AS ca ON ca.user_id = c.user_id 
WHERE ca.type IN('downloaded_software', 'filled_download_form', 'purchased') 
GROUP BY c.user_id
HAVING COUNT(DISTINCT ca.type) = 3
ORDER BY c.user_id 
LIMIT 0, 100

An SQLfiddle to test with .

EDIT: To answer your question from the comments, if you need to exclude a type, you can't easily use GROUP BY to find the results. You can either do a self join per type (left join the excluded one and check that it results in no row);

SELECT SQL_CALC_FOUND_ROWS c.user_id 
FROM customer AS c 
JOIN customer_activity AS ca1
  ON ca1.user_id = c.user_id AND ca1.type = 'downloaded_software'
JOIN customer_activity AS ca2
  ON ca2.user_id = c.user_id AND ca2.type = 'filled_download_form'
LEFT JOIN customer_activity AS ca3
  ON ca3.user_id = c.user_id AND ca3.type = 'purchased'
WHERE ca3.user_id IS NULL 
ORDER BY c.user_id 
LIMIT 0, 100

...or - not as efficient but perhaps easier if you're auto generating the query - you can do it using 3 simple subqueries using IN and NOT IN to select if the type should be included or not...

SELECT SQL_CALC_FOUND_ROWS c.user_id 
FROM customer AS c
WHERE c.user_id IN (
  SELECT user_id FROM customer_activity WHERE type='downloaded_software'
) AND c.user_id IN (
  SELECT user_id FROM customer_activity WHERE type='filled_download_form'
) AND c.user_id NOT IN (
  SELECT user_id FROM customer_activity WHERE type='purchased'
) 
ORDER BY c.user_id
LIMIT 0,100;

An SQLfiddle showing both in action .

Answer 2

Disclaimer: in a comment in the answer of Joachim Isaksson I've suggested a variation on one of his query to the OP, who asked clarification, this is it.

Starting from the query with the modification

SELECT SQL_CALC_FOUND_ROWS c.user_id 
FROM customer AS c 
JOIN customer_activity AS ca 
  ON ca.user_id = c.user_id 
WHERE ca.type IN('downloaded_software',
                 'filled_download_form',
                 'purchased') 
GROUP BY c.user_id

ORDER BY c.user_id 
LIMIT 0, 100

the part in bold is my suggested edit.

If something it's not clear outside the part I modified you should ask to Joachim Isaksson, as he is the one who wrote the query.

My edit does what it say on the tin: the first condition check that there are only two of the three valid values of type , the second one check that 'purchased' is the one left out. The second condition is equivalent to

SUM(CASE WHEN ca.type = 'purchased' THEN 1 ELSE 0 END) = 0

that is maybe more simple to read.

The whole query is equivalent to

SELECT SQL_CALC_FOUND_ROWS c.user_id 
FROM customer AS c 
JOIN customer_activity AS ca 
  ON ca.user_id = c.user_id 
WHERE ca.type IN('downloaded_software',
                 'filled_download_form',
                 'purchased') 
GROUP BY c.user_id
HAVING COUNT(DISTINCT 
             CASE WHEN ca.type = 'downloaded_software' THEN 1 ELSE NULL END) = 1
   AND COUNT(DISTINCT 
             CASE WHEN ca.type = 'filled_download_form' THEN 1 ELSE NULL END) = 1
   AND COUNT(DISTINCT 
             CASE WHEN ca.type = 'purchased' THEN 1 ELSE NULL END) = 0
ORDER BY c.user_id 
LIMIT 0, 100

(if you only have those 3 type the WHERE is not necessary)

If you're writing the query from a programming language I will use this as the template

SELECT SQL_CALC_FOUND_ROWS c.user_id 
FROM customer AS c 
JOIN customer_activity AS ca 
  ON ca.user_id = c.user_id 
WHERE ca.type IN('downloaded_software',
                 'filled_download_form',
                 'purchased') 
GROUP BY c.user_id
HAVING COUNT(DISTINCT 
             CASE WHEN ca.type = 'downloaded_software' 
                  THEN 1 ELSE NULL END) = ?downloaded?
   AND COUNT(DISTINCT 
             CASE WHEN ca.type = 'filled_download_form' 
                  THEN 1 ELSE NULL END) = ?filled?
   AND COUNT(DISTINCT 
             CASE WHEN ca.type = 'purchased' 
                  THEN 1 ELSE NULL END) = ?purchased?
ORDER BY c.user_id 
LIMIT 0, 100

with ?downloaded? , ?filled? and ?purchased? as parameters. 1 mean that the type need to be present, 0 mean that the parameter need to be missing

To answer the other question For example, only target customers who have neither filled_download_form nor purchased. What would be the query for that? just fill the parameters accordingly.