I am having a lot of trouble with trying to construct a query that will give me the name of each customer and the number of different types of accounts each has. The three types are Checkings, Savings, and CD.
customers:
+--------+--------+
| cid | name |
+--------+--------+
| 1 | a |
| 2 | b |
| 3 | c |
+--------+--------+
accounts:
+-----------+-----------+
| aid | type |
+-----------+-----------+
| 1 | Checkings |
| 2 | Savings |
| 3 | Checkings |
| 4 | CD |
| 5 | CD |
| 6 | Checkings |
+-----------+-----------+
transactions:
+--------+--------+--------+
| tid | cid | aid |
+--------+--------+--------+
| 1 | 1 | 1 |
| 2 | 1 | 2 |
| 3 | 2 | 3 |
| 4 | 3 | 4 |
| 5 | 1 | 5 |
| 6 | 3 | 4 |
| 7 | 1 | 6 |
+--------+--------+--------+
The expected answer would be:
a, 3
b, 1
c, 1
Getting the names is simple enough, but how can I keep count of each individual's account as well as compare the accounts to make sure that it is not the same type?
just add DISTINCT inside the COUNT
SELECT a.cid, a.name, COUNT(DISTINCT c.type) totalCount
FROM customers a
INNER JOIN transactions b
ON a.cis = b.cid
INNER JOIN accounts c
ON b,aid = c.aid
GROUP BY a.cid, a.name
Query:
SQLFiddleExample
SELECT
a."name",
COUNT(DISTINCT c."type") totalCount
FROM customers a
INNER JOIN transactions b
ON a."cid" = b."cid"
INNER JOIN accounts c
ON b."aid" = c."aid"
GROUP BY a."cid", a."name"
ORDER BY totalCount DESC
Result:
| NAME | TOTALCOUNT |
---------------------
| a | 3 |
| b | 1 |
| c | 1 |
Related
I have a table like this in MS SQL SERVER
+------+------+
| ID | Cust |
+------+------+
| 1 | A |
| 1 | A |
| 1 | B |
| 1 | B |
| 2 | A |
| 2 | A |
| 2 | A |
| 2 | B |
| 3 | A |
| 3 | B |
| 3 | B |
| 3 | C |
| 3 | C |
+------+------+
I don't know the values in column "Cust" and I want to return all rows where the value of "Cust" appears multiple times and where at least one of the "ID" values is "1".
Like this:
+------+------+
| ID | Cust |
+------+------+
| 1 | A |
| 1 | A |
| 1 | B |
| 1 | B |
| 2 | A |
| 2 | A |
| 2 | A |
| 2 | B |
| 3 | A |
| 3 | B |
| 3 | B |
+------+------+
Any ideas? I can't find it.
You may use COUNT window function as the following:
SELECT ID, Cust
FROM
(
SELECT ID, Cust,
COUNT(*) OVER (PARTITION BY Cust) cn,
COUNT(CASE WHEN ID=1 THEN 1 END) OVER (PARTITION BY Cust) cn2
FROM table_name
) T
WHERE cn>1 AND cn2>0
ORDER BY ID, Cust
COUNT(*) OVER (PARTITION BY Cust) to check if the value of "Cust" appears multiple times.
COUNT(CASE WHEN ID=1 THEN 1 END) OVER (PARTITION BY Cust) to check that at least one of the "ID" values is "1".
See a demo.
I have 3 tables. The link between the first and the second table is REQ_ID and the link between the second and the third table is ENC_ID. There is no direct link between the first and the third table.
INS_RCPT
+----+--------+------+----------+
| ID | REQ_ID | CURR | RCPT_AMT |
+----+--------+------+----------+
| 1 | 1 | USD | 100 |
| 2 | 2 | USD | 200 |
| 3 | 3 | USD | 300 |
+----+--------+------+----------+
ENC_LOG
+----+--------+--------+-------------+
| ID | REQ_ID | ENC_ID | ENC_LOG_AMT |
+----+--------+--------+-------------+
| 1 | 1 | 1 | 20 |
| 2 | 1 | 2 | 50 |
| 3 | 1 | 3 | 30 |
| 4 | 2 | 4 | 20 |
+----+--------+--------+-------------+
ENC_RCPT
+----+--------+--------------+
| ID | ENC_ID | ENC_RCPT_AMT |
+----+--------+--------------+
| 1 | 1 | 10 |
| 2 | 1 | 10 |
| 3 | 2 | 15 |
| 4 | 2 | 25 |
| 5 | 2 | 10 |
| 6 | 3 | 12 |
| 7 | 3 | 18 |
| 8 | 4 | 10 |
+----+--------+--------------+
I would like to have output as follows:
+----+--------+------+----------+-------------+--------------+
| ID | REQ_ID | CURR | RCPT_AMT | ENC_LOG_AMT | ENC_RCPT_AMT |
+----+--------+------+----------+-------------+--------------+
| 1 | 1 | USD | 100 | 100 | 100 |
| 2 | 2 | USD | 200 | 20 | 10 |
| 3 | 3 | USD | 300 | 0 | 0 |
+----+--------+------+----------+-------------+--------------+
I am using SQL Server to write this query. Any help is appreciated.
One approach would be to join the first table to two subqueries which compute the sums separately:
SELECT
ir.ID,
ir.REQ_ID,
ir.CURR,
ir.RCPT_AMT,
el.ENC_LOG_AMT,
er.ENC_RCPT_AMT
FROM INS_RCPT ir
LEFT JOIN
(
SELECT REQ_ID, SUM(ENC_LOG_AMT) AS ENC_LOG_AMT
FROM ENC_LOG
GROUP BY REQ_ID
) el
ON ir.REQ_ID = el.REQ_ID
LEFT JOIN
(
SELECT t1.REQ_ID, SUM(t2.ENC_RCPT_AMT) AS ENC_RCPT_AMT
FROM ENC_LOG t1
INNER JOIN ENC_RCPT t2 ON t1.ENC_ID = t2.ENC_ID
GROUP BY t1.REQ_ID
) er
ON ir.REQ_ID = er.REQ_ID
Demo
Note that your question includes a curve ball. The second subquery needs to return aggregates of the receipt table by REQ_ID, even though this field does not appear in that table. As a result, we actually need to join ENC_LOG to ENC_RCPT in that subquery, and then aggregate by REQ_ID.
You can try the below query. Also change the join from left to inner as per your requirement.
select a.id,a.req_id,a.curr,sum(a.rcpt_amt) rcpt_amt,sum(a.enc_log_amt) enc_log_amt,sum(c.enc_rcpt_amt) enc_rcpt_amt
from
(
select a.id id ,a.req_id req_id ,a.curr curr,sum(rcpt_amt) as rcpt_amt,sum(enc_log_amt) as enc_log_amt
from ins_rcpt a
left join enc_log b
on a.req_id=b.req_id
group by id,req_id,curr
) a
left join enc_rcpt c
on a.enc_id = c.enc_id
group by id,req_id,curr;
I have 3 tables as shown:
Video
+----+--------+-----------+
| id | name | videoSize |
+----+--------+-----------+
| 1 | video1 | 1MB |
| 2 | video2 | 2MB |
| 3 | video3 | 3MB |
+----+--------+-----------+
Survey
+----+---------+-----------+
| id | name | questions |
+----+---------+-----------+
| 1 | survey1 | 1 |
| 2 | survey2 | 2 |
| 3 | survey3 | 3 |
+----+---------+-----------+
Sequence
+----+---------+-----------+----------+
| id | videoId | surveyId | sequence |
+----+---------+-----------+----------+
| 1 | null | 1 | 1 |
| 2 | 2 | null | 2 |
| 3 | null | 3 | 3 |
+----+---------+-----------+----------+
I would like to query Sequence and join on both of video and survey tables and merge common columns without specifying the column names (in this case name) like this:
Query Result:
+----+---------+-----------+----------+---------+-----------+-----------+
| id | videoId | surveyId | sequence | name | videoSize | questions |
+----+---------+-----------+----------+---------+-----------+-----------+
| 1 | null | 1 | 1 | survey1 | null | 1 |
| 2 | 2 | null | 2 | video2 | 2MB | null |
| 3 | null | 3 | 3 | survey3 | null | 3 |
+----+---------+-----------+----------+---------+-----------+-----------+
Is this possible?
BTW the below sql doesn't work as it doesn't merge on the name field:
SELECT * FROM "Sequence"
LEFT JOIN "Survey" ON "Survey"."id" = "Sequence"."surveyId"
LEFT JOIN "Video" ON "Video"."id" = "Sequence"."videoId"
This query will show what you want:
select
s.*,
coalesce(y.name, v.name) as name, -- picks the right column
v.videoSize,
y.questions
from sequence s
left join survey y on y.id = s.surveyId
left join video v on v.id = s.videoId
However, the SQL standard requires you to name the columns you want. The only exception being * as shown above.
Is it possible to do something like:
select
avg(count(distinct user_id))
over (partition by some_date) as average_users_per_day
from user_activity
group by user_type
(notably, the partition by column, some_date, is not in the group by columns)
The idea I'm going for is something like: the average users per day by user type.
I know how to do it using subqueries (see below), but I'd like to know if there is a nice way using only over (partition by ...) and group by.
Notes:
From reading this answer, my understanding (correct me if I'm wrong) is that the following query:
select
avg(count(distinct a)) over (partition by b)
from foo
group by b
can be expanded equivalently to:
select
avg(count_distinct_a)
from (
select
b,
count(distinct a) as count_distinct_a
from foo
group by b
)
group by b
And from that, I can tweak it a bit to achieve what I want:
select
avg(count_distinct_user_id) as average_users_per_day
from (
select
user_type,
count(distinct user_id) as count_distinct_user_id
from user_activity
group by user_type, some_date
)
group by user_type
(notably, the inner group by user_type, some_date differs from the outer group by user_type)
I'd like to be able to tell the partition by-group by interaction to use a "sub-group-by" for the windowing part. Please let me know if my understanding of partition by/group by is completely off.
EDIT: Some sample data and desired output.
Source table:
+---------+-----------+-----------+
| user_id | user_type | some_date |
+---------+-----------+-----------+
| 1 | a | 1 |
| 1 | a | 2 |
| 2 | a | 1 |
| 3 | a | 2 |
| 3 | a | 2 |
| 4 | b | 2 |
| 5 | b | 1 |
| 5 | b | 3 |
| 5 | b | 3 |
| 6 | c | 1 |
| 7 | c | 1 |
| 8 | c | 4 |
| 9 | c | 2 |
| 9 | c | 3 |
| 9 | c | 4 |
+---------+-----------+-----------+
Sample intermediate table (for reasoning with):
+-----------+-----------+---------------------+
| user_type | some_date | distinct_user_count |
+-----------+-----------+---------------------+
| a | 1 | 2 |
| a | 2 | 2 |
| b | 1 | 1 |
| b | 2 | 1 |
| b | 3 | 1 |
| c | 1 | 2 |
| c | 2 | 1 |
| c | 3 | 1 |
| c | 4 | 2 |
+-----------+-----------+---------------------+
SQL is: select user_type, some_date, count(distinct user_id) from user_activity group by user_type, some_date.
Desired result:
+-----------+---------------------+
| user_type | average_daily_users |
+-----------+---------------------+
| a | 2 |
| b | 1 |
| c | 1.5 |
+-----------+---------------------+
Sorry for the confusing title; however a description and illustration should hopefully clear it up.
Essentially, I have the table A representing instances of a transfer of an 'amount' between rows of table B. I wish to join A with B so that I can display the details of the transfer:
================= A ===================
+-----+-----------+----------+--------+
| AID | fromID(FK) | toID(FK) | amount |
+-----+-----------+----------+--------+
| 1 | 1 | 5 | 100 |
| 2 | 1 | 3 | 150 |
| 3 | 5 | 3 | 500 |
| 4 | 1 | 5 | 200 |
| 5 | 4 | 5 | 800 |
| 6 | 3 | 5 | 15 |
+----+------------+----------+--------+
and
==== B =====
+----+------+
| BID | name |
+----+------+
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
| 5 | e |
+----+------+
I wish to join them and produce a "from name" column and a "to name" like:
+-----+------+----+--------+
| AID | from | to | amount |
+-----+------+----+--------+
| 1 | a | e | 100 |
| 2 | a | c | 150 |
| 3 | e | c | 500 |
| 4 | a | e | 200 |
| 5 | d | e | 800 |
| 6 | c | e | 15 |
+-----+------+----+--------+
You can join a on b twice:
SELECT aid, from_b.name, to_b.name, amount
FROM a
JOIN b from_b ON from_b.bid = a.fromid
JOIN b to_b ON to_b.bid = a.toid
Do a JOIN between the tables like below but you will have to join table B twice
select a.AID,
b.name as [from],
b1.name as [to],
a.amount
from A a
join B b on a.fromID(FK) = b.BID
join B b1 on a.toID(FK) = B.bid;
You can do this with out join.
Fiddle with sample data
select aid,
(select name from b where a.fromid = bid) as "from",
(select name from b where a.toid = bid) as "to",
amount
from a