SQL query for counting multiple strings with one output - mysql

Question

I have a database including certain strings, such as '{TICKER|IBM}' to which I will refer as ticker-strings. My target is to count the amount of ticker-strings per day for multiple strings.
My database table 'tweets' includes the rows 'tweet_id', 'created at' (dd/mm/yyyy hh/mm/ss) and 'processed text'. The ticker-strings, such as '{TICKER|IBM}', are within the 'processed text' row.
At this moment, I have a working SQL query for counting one ticker-string (thanks to the help of other Stackoverflow-ers). What I would like to have is a SQL query in which I can count multiple strings (next to '{TICKER|IBM}' also '{TICKER|GOOG}' and '{TICKER|BAC}' for instance).
The working SQL query for counting one ticker-string is as follows:
SELECT d.date, IFNULL(t.count, 0) AS tweet_count
FROM all_dates AS d
LEFT JOIN (
SELECT COUNT(DISTINCT tweet_id) AS count, DATE(created_at) AS date
FROM tweets
WHERE processed_text LIKE '%{TICKER|IBM}%'
GROUP BY date) AS t
ON d.date = t.date
The eventual output should thus give a column with the date, a column with {TICKER|IBM}, a column with {TICKER|GOOG} and one with {TICKER|BAC}.
I was wondering whether this is possible and whether you have a solution for this? I have more than 100 different ticker-strings. Of course, doing them one-by-one is an option, but it is a very time-consuming one.

Answer 1

If I understand correctly, you can do this with conditional aggregation:
SELECT d.date, coalesce(IBM, 0) as IBM, coalesce(GOOG, 0) as GOOG, coalesce(BAC, 0) AS BAC
FROM all_dates d LEFT JOIN
(SELECT DATE(created_at) AS date,
COUNT(DISTINCT CASE WHEN processed_text LIKE '%{TICKER|IBM}%' then tweet_id
END) as IBM,
COUNT(DISTINCT CASE WHEN processed_text LIKE '%{TICKER|GOOG}%' then tweet_id
END) as GOOG,
COUNT(DISTINCT CASE WHEN processed_text LIKE '%{TICKER|BAC}%' then tweet_id
END) as BAC
FROM tweets
GROUP BY date
) t
ON d.date = t.date;

Answer 2

I'd return the specified resultset like this, adding expressions to the SELECT list for each "ticker" I want returned as a separate column:
SELECT d.date
, IFNULL(SUM(t.processed_text LIKE '%{TICKER|IBM}%' ),0) AS `cnt_ibm`
, IFNULL(SUM(t.processed_text LIKE '%{TICKER|GOOG}%'),0) AS `cnt_goog`
, IFNULL(SUM(t.processed_text LIKE '%{TICKER|BAC}%' ),0) AS `cnt_goog`
, IFNULL(SUM(t.processed_text LIKE '%{TICKER|...}%' ),0) AS `cnt_...`
FROM all_dates d
LEFT
JOIN tweets t
ON t.created_at >= d.date
AND t.created_at < d.date + INTERVAL 1 DAY
GROUP BY d.date
NOTES: The expressions within the SUM aggregates above are evaluated as booleans, so they return 1 (if true), 0 (if false), or NULL. I'd avoid wrapping the created_at column in a DATE() function, and use a range scan instead, especially if a predicate is added (WHERE clause) that restricts the values ofdatebeing returned fromall_dates`.
As an alternative, expressions like this will return an equivalent result:
, SUM(IF(t.process_text LIKE '%{TICKER|IBM}%' ,1,0)) AS `cnt_ibm`