SQL select query for ranking - sql

I have this table called logs that logs a who input or output data.
Now I wan't to get the statistics of who has the most contributions and rank them.
Columns are
Occur_Time | iUser_id | iUsername | oUser_id | oUsername
--iUser_id is the input persons index from another table that lists the username.
--iUsername is the input persons name.
--oUser_id is the index of the person who took the input away.
--oUsername is the name of the person who took the input away.
Now I wan't to know who has the most input.
My logic:
Example:
User_id is 1, name is One.
Check how many times 1 is repeated on iUser_id = 100 times.
Check how many times 1 is repeated on oUser_id = 10 times.
User_id=1 has contributed 90 times.
Then sort by who has most contribution.
Thank you.

(untested):
SELECT L.iUsername,
((SELECT COUNT(1) FROM logs WHERE iUsername=L.iUsername) -
(SELECT COUNT(1) FROM logs WHERE oUsername=L.iUsername)) as rank
FROM logs L
GROUP BY L.iUsername
ORDER BY rank ASC

The Rank feature is probably what you are looking for.
http://msdn.microsoft.com/en-us/library/ms176102.aspx

Try that query.
Select user_id, count(user_id) from tablename group by user_id;

Related

Count with Group By always shows '1'

I'm trying to count the number of articles mentioning Donald Trump exist in a Google BigQuery table.
SELECT
sourcecommonname,
COUNT(DISTINCT sourcecommonname) counter
FROM
`israel_media`
WHERE
persons LIKE '%donald trump%'
GROUP BY
sourcecommonname
Results are always
sourcecommonname
counter
first_newspaper
1
second_newspaper
1
third_newspaper
1
forth_newspaper
1
What am I not seeing?
Of course. You are counting distinct values. But there is only one value per group. That is what the group by does.
Perhaps you just want count() without distinct:
SELECT sourcecommonname,
COUNT(*) as counter
FROM `israel_media`
WHERE persons LIKE '%donald trump%'
GROUP BY sourcecommonname

Alternative for GROUP BY and STUFF in SQL

I am writing some SQL queries in AWS Athena. I have 3 tables search, retrieval and intent. In search table I have 2 columns id and term i.e.
id term
1 abc
1 bcd
2 def
1 ghd
What I want is to write a query to get:
id term
1 abc, bcd, ghd
2 def
I know this can be done using STUFF and FOR XML PATH but, in Athena all the features of SQL are yet not supported. Is there any other way to achieve this. My current query is:
select search.id , STUFF(
(select ',' + search.term
from search
FOR XML PATH('')),1,1,'')
FROM search
group by search.id
Also, I have one more question. I have retrieval table that consist of 3 columns i.e.:
id time term
1 0 abc
1 20 bcd
1 100 gfh
2 40 hfg
2 60 lkf
What I want is:
id time term
1 100 gfh
2 60 lkf
I want to write a query to get the id and term on the basis of max value of time. Here is my current query:
select retrieval.id, max(retrieval.time), retrieval.term
from search
group by retrieval.id, retrieval.term
order by max(retrieval.time)
I am getting duplicate id's along with the term. I think it is because, I am doing group by on id and term both. But, I am not sure how can I achieve it without using group by.
The XML method is brokenness in SQL Server. No reason to attempt it in any other database.
One method uses arrays:
select s.id, array_agg(s.term)
from search s
group by s.id;
Because the database supports arrays, you should learn to use them. You can convert the array to a string:
select s.id, array_join(array_agg(s.term), ',') as terms
from search s
group by s.id;
Group by is a group operation: think that you are clubbing the results and have to find min, max, count etc.
I am answering only one question. Use it to find the answer to question 1
For question 2:
select
from (select id, max(time) as time
from search
group by id, term
order by max(time)
) search_1, search as search_2
where search_1.id = search_2.id
and search_1.time = search_2.time

sqlite query unsorted result

I have list of Ids 31165,31160,31321,31322,31199,31136 which is dynamic.
When I run query
select id,name from master_movievod where id in(31165,31160,31321,31322,31199,31136);
I get following result
31136|Independence Day
31160|Planet of the Apes
31165|Mrs. Doubtfire
31199|Moulin Rouge
31321|Adult Movie 2
31322|Adult Movie 3
This is sorted list in ascending order.
I want the list in the same order which I give as input like
31165|Mrs. Doubtfire
31160|Planet of the Apes
31321|Adult Movie 2
31322|Adult Movie 3
31199|Moulin Rouge
31136|Independece Day
Without an order by clause, there's no guarantee on the order a database returns the results to you. SQLite, unfortunately, doesn't have something like MySQL's field for custom sorting, but you can jimmy-rig something with a case expression:
SELECT id, name
FROM master_movievod
WHERE id IN (31165, 31160, 31321, 31322, 31199, 31136)
ORDER BY CASE ID WHEN 31165 THEN 0
WHEN 31160 THEN 1
WHEN 31321 THEN 2
WHEN 31322 THEN 3
WHEN 31199 THEN 4
WHEN 31136 THEN 5
END ASC
Unfortunately, SQLite does not have an option like MySQL's FIELD for doing a custom ordering. You are left with two options. The first is that you could create a custom table containing the ordering you want and use that to sort. This option isn't very attractive. The second (and easier) option is to use ORDER BY CASE to achieve the order you want:
SELECT id, name FROM master_movievod
WHERE id IN (31165,31160,31321,31322,31199,31136)
ORDER BY
CASE id
WHEN 31165 THEN 0
WHEN 31160 THEN 1
WHEN 31321 THEN 2
WHEN 31322 THEN 3
WHEN 31199 THEN 4
WHEN 31136 THEN 5
END ASC

sql statement to select previous rows to a search param

Im after an sql statement (if it exists) or how to set up a method using several sql statements to achieve the following.
I have a listbox and a search text box.
in the search box, user would enter a surname e.g. smith.
i then want to query the database for the search with something like this :
select * FROM customer where surname LIKE searchparam
This would give me all the results for customers with surname containing : SMITH . Simple, right?
What i need to do is limit the results returned. This statement could give me 1000's of rows if the search param was just S.
What i want is the result, limited to the first 20 matches AND the 10 rows prior to the 1st match.
For example, SMI search:
Sives
Skimmings
Skinner
Skipper
Slater
Sloan
Slow
Small
Smallwood
Smetain
Smith ----------- This is the first match of my query. But i want the previous 10 and following 20.
Smith
Smith
Smith
Smith
Smoday
Smyth
Snedden
Snell
Snow
Sohn
Solis
Solomon
Solway
Sommer
Sommers
Soper
Sorace
Spears
Spedding
Is there anyway to do this?
As few sql statements as possible.
Reason? I am creating an app for users with slow internet connections.
I am using POSTGRESQL v9
Thanks
Andrew
WITH ranked AS (
SELECT *, ROW_NUMBER() over (ORDER BY surname) AS rowNumber FROM customer
)
SELECT ranked.*
FROM ranked, (SELECT MIN(rowNumber) target FROM ranked WHERE surname LIKE searchparam) found
WHERE ranked.rowNumber BETWEEN found.target - 10 AND found.target + 20
ORDER BY ranked.rowNumber
SQL Fiddle here. Note that the fiddle uses the example data, and I modified the range to 3 entries before and 6 entries past.
I'm assuming that you're looking for a general algorithm ...
It sounds like you're looking for a combination of finding the matches "greater than or equal to smith", and "less than smith".
For the former you'd order by surname and limit the result to 20, and for the latter you'd order by surname descending and limit to 10.
The two result sets can then be added together as arrays and reordered.
I think you need to use ROW_NUMBER() (see this link).
WITH cust1 AS (
SELECT *, ROW_NUMBER() OVER (ORDER BY surname) as numRow FROM customer
)
SELECT c1.surname, c1.numRow, x.flag
FROM cust1 c1, (SELECT *,
case when numRow = (SELECT MIN(numRow) FROM cust1 WHERE surname='Smith') then 1 else 0 end as flag
FROM cust1) x
WHERE x.flag = 1 and c1.numRow BETWEEN x.numRow - 1 AND x.numRow + 1
ORDER BY c1.numRow
SQLFiddle here.
This works, but the flag finally isn't necessary and it would be a query like PinnyM posts.
A variation on #PinnyM's solution:
WITH ranked AS (
SELECT
*,
ROW_NUMBER() over (ORDER BY surname) AS rowNumber
FROM customer
),
minrank AS (
SELECT
*,
MIN(CASE WHEN surname LIKE searchparam THEN rowNumber END) OVER () AS target
FROM ranked
)
SELECT
surname
FROM minrank
WHERE rowNumber BETWEEN target - 10 AND target + 20
;
Instead of two separate calls to the ranked CTE, one to get the first match's row number and the other to read the results from, another CTE is introduced to serve both purposes. Can't speak for PostgreSQL but in SQL Server this might result in a better execution plan for the query, although in either case the real efficiency would still need to be verified by proper testing.

How to group by a column

Hi I know how to use the group by clause for sql. I am not sure how to explain this so Ill draw some charts. Here is my original data:
Name Location
----------------------
user1 1
user1 9
user1 3
user2 1
user2 10
user3 97
Here is the output I need
Name Location
----------------------
user1 1
9
3
user2 1
10
user3 97
Is this even possible?
The normal method for this is to handle it in the presentation layer, not the database layer.
Reasons:
The Name field is a property of that data row
If you leave the Name out, how do you know what Location goes with which name?
You are implicitly relying on the order of the data, which in SQL is a very bad practice (since there is no inherent ordering to the returned data)
Any solution will need to involve a cursor or a loop, which is not what SQL is optimized for - it likes working in SETS not on individual rows
Hope this helps
SELECT A.FINAL_NAME, A.LOCATION
FROM (SELECT DISTINCT DECODE((LAG(YT.NAME, 1) OVER(ORDER BY YT.NAME)),
YT.NAME,
NULL,
YT.NAME) AS FINAL_NAME,
YT.NAME,
YT.LOCATION
FROM YOUR_TABLE_7 YT) A
As Jirka correctly pointed out, I was using the Outer select, distinct and raw Name unnecessarily. My mistake was that as I used DISTINCT , I got the resulted sorted like
1 1
2 user2 1
3 user3 97
4 user1 1
5 3
6 9
7 10
I wanted to avoid output like this.
Hence I added the raw id and outer select
However , removing the DISTINCT solves the problem.
Hence only this much is enough
SELECT DECODE((LAG(YT.NAME, 1) OVER(ORDER BY YT.NAME)),
YT.NAME,
NULL,
YT.NAME) AS FINAL_NAME,
YT.LOCATION
FROM SO_BUFFER_TABLE_7 YT
Thanks Jirka
If you're using straight SQL*Plus to make your report (don't laugh, you can do some pretty cool stuff with it), you can do this with the BREAK command:
SQL> break on name
SQL> WITH q AS (
SELECT 'user1' NAME, 1 LOCATION FROM dual
UNION ALL
SELECT 'user1', 9 FROM dual
UNION ALL
SELECT 'user1', 3 FROM dual
UNION ALL
SELECT 'user2', 1 FROM dual
UNION ALL
SELECT 'user2', 10 FROM dual
UNION ALL
SELECT 'user3', 97 FROM dual
)
SELECT NAME,LOCATION
FROM q
ORDER BY name;
NAME LOCATION
----- ----------
user1 1
9
3
user2 1
10
user3 97
6 rows selected.
SQL>
I cannot but agree with the other commenters that this kind of problem does not look like it should ever be solved using SQL, but let us face it anyway.
SELECT
CASE main.name WHERE preceding_id IS NULL THEN main.name ELSE null END,
main.location
FROM mytable main LEFT JOIN mytable preceding
ON main.name = preceding.name AND MIN(preceding.id) < main.id
GROUP BY main.id, main.name, main.location, preceding.name
ORDER BY main.id
The GROUP BY clause is not responsible for the grouping job, at least not directly. In the first approximation, an outer join to the same table (LEFT JOIN below) can be used to determine on which row a particular value occurs for the first time. This is what we are after. This assumes that there are some unique id values that make it possible to arbitrarily order all the records. (The ORDER BY clause does NOT do this; it orders the output, not the input of the whole computation, but it is still necessary to make sure that the output is presented correctly, because the remaining SQL does not imply any particular order of processing.)
As you can see, there is still a GROUP BY clause in the SQL, but with a perhaps unexpected purpose. Its job is to "undo" a side effect of the LEFT JOIN, which is duplication of all main records that have many "preceding" ( = successfully joined) records.
This is quite normal with GROUP BY. The typical effect of a GROUP BY clause is a reduction of the number of records; and impossibility to query or test columns NOT listed in the GROUP BY clause, except through aggregate functions like COUNT, MIN, MAX, or SUM. This is because these columns really represent "groups of values" due to the GROUP BY, not just specific values.
If you are using SQL*Plus, use the BREAK function. In this case, break on NAME.
If you are using another reporting tool, you may be able to compare the "name" field to the previous record and suppress printing when they are equal.
If you use GROUP BY, output rows are sorted according to the GROUP BY columns as if you had an ORDER BY for the same columns. To avoid the overhead of sorting that GROUP BY produces, add ORDER BY NULL:
SELECT a, COUNT(b) FROM test_table GROUP BY a ORDER BY NULL;
Relying on implicit GROUP BY sorting in MySQL 5.6 is deprecated. To achieve a specific sort order of grouped results, it is preferable to use an explicit ORDER BY clause. GROUP BY sorting is a MySQL extension that may change in a future release; for example, to make it possible for the optimizer to order groupings in whatever manner it deems most efficient and to avoid the sorting overhead.
For full information - http://academy.comingweek.com/sql-groupby-clause/
SQL GROUP BY STATEMENT
SQL GROUP BY clause is used in collaboration with the SELECT statement to arrange identical data into groups.
Syntax:
1. SELECT column_nm, aggregate_function(column_nm) FROM table_nm WHERE column_nm operator value GROUP BY column_nm;
Example :
To understand the GROUP BY clauserefer the sample database.Below table showing fields from “order” table:
1. |EMPORD_ID|employee1ID|customerID|shippers_ID|
Below table showing fields from “shipper” table:
1. | shippers_ID| shippers_Name |
Below table showing fields from “table_emp1” table:
1. | employee1ID| first1_nm | last1_nm |
Example :
To find the number of orders sent by each shipper.
1. SELECT shipper.shippers_Name, COUNT (orders.EMPORD_ID) AS No_of_orders FROM orders LEFT JOIN shipper ON orders.shippers_ID = shipper.shippers_ID GROUP BY shippers_Name;
1. | shippers_Name | No_of_orders |
Example :
To use GROUP BY statement on more than one column.
1. SELECT shipper.shippers_Name, table_emp1.last1_nm, COUNT (orders.EMPORD_ID) AS No_of_orders FROM ((orders INNER JOIN shipper ON orders.shippers_ID=shipper.shippers_ID) INNER JOIN table_emp1 ON orders.employee1ID = table_emp1.employee1ID)
2. GROUP BY shippers_Name,last1_nm;
| shippers_Name | last1_nm |No_of_orders |
for more clarification refer my link
http://academy.comingweek.com/sql-groupby-clause/