for a table such as:
employeeID | groupCode
1 red111
2 red111
3 blu123
4 blu456
5 red553
6 blu423
7 blu341
how can I count the number of employeeIDs that are in parent groups (such as red or blu, but there are many more groups in the real table) that have a total number of group members greater than 2 (so all those with blu in this particular example) excluding themselves.
To expand: groupCode consists of a parent group (three letters), followed by some numbers for the subgroup.
using a self-join, or at least without using a group by statement.
So far I have:
SELECT T1.employeeID
FROM TABLE T1, TABLE T2
WHERE T1.groupCode <> T2.groupCode
AND SUBSTR(T1.groupCode, 1, 3) = SUBSTR(T2.gorupCode, 1, 3);
but that doesn't do much for me...
Add an index on the first 3 characters of EMPLOYEE.
Then try this one:
SELECT ed.e3
, COUNT(*)
FROM EMPLOYEE e
JOIN
( SELECT DISTINCT
SUBSTR(groupCode, 1, 3) AS e3
FROM EMPLOYEE
) ed
ON e.groupCode LIKE CONCAT(ed.e3, '%')
GROUP BY ed.e3
HAVING COUNT(*) >= 3 --- or whatever is wanted
What about
SELECT substring(empshirtno, 1, 3),
Count(SELECT 1 from myTable as myTable2
WHERE substring(mytable.empshirtno, 1, 3) = substring(mytable2.empshirtno, 1, 3))
FROM MyTable
GROUP BY substring(mytable2.empshirtno, 1, 3)
maybe counting from a subquery is speedier with an index
Related
I have one table like bellow. Each id is unique.
id
times_of_going_out
fef666
2
S335gg
1
9a2c50
1
and another table like this one ↓. In this second table the "id" is not unique, there are different "category_name" for a single id.
id
category_name
city
S335gg
Games & Game Supplies
tk
9a2c50
Telephone Companies
os
9a2c50
Recreation Centers
ky
fef666
Recreation Centers
ky
I want to find the difference between destinations(category_name) of people who go out often(times_of_going_out<5) and people who don't go out often(times_of_going_out<=5).
** Both tables are a small sample of large tables.
・ Where do people who go out twice often go?
・ Where do people who go out ６times often go?
Thank you
The expected result could be something like
less than 5
more than 5
top ten “category_name” for uid’s with "times_of_going_out" less than 5 times
top ten “category_name” for uid’s with "times_of_going_out" more than 5 times
Steps:
combining data and aggregating total time_going_out
creating the categories that you need : less than equal to 5 and more than 5. if you don't need equal to 5, you can adjust the code
ranking both categories with top 10, using dense_rank(). this will produce the rank from 1 - 10 based on the total time_going out
filtering the cases so it takes top 10 values for both categories
with main as (
select
category_name,
sum(coalesce(times_of_going_out,0)) as total_time_per_category
from table1 as t1
left join table2 as t2
on t1.id = t2.id
group by 1
),
category as (
select
*,
if(total_time_per_category >= 5, 'more than 5', 'less than equal to 5') as is_more_than_5_times
from main
),
ranking_ as (
select *,
case when
is_more_than_5_times = 'more than 5' then
dense_rank() over (partition by is_more_than_5_times order by total_time_per_category desc)
else NULL
end AS rank_more_than_5,
case when
is_more_than_5_times = 'less than equal to 5' then
dense_rank() over (partition by is_more_than_5_times order by total_time_per_category)
else NULL
end AS rank_less_than_equal_5
from category
)
select
is_more_than_5_times,
string_agg(category_name,',') as list
from ranking_
where rank_less_than_equal_5 <=10 or rank_more_than_5 <= 10
group by 1
I've a data base with two tables.
Table Players Table Wins
ID Name ID Player_won
1 Mick 1 2
2 Frank 2 1
3 Sarah 3 4
4 Eva 4 5
5 Joe 5 1
I need a SQL query which show "The players who have not won any game".
I tried but I don't know even how to begin.
Thank you
You need all the rows from players that don't have corresponding rows in wins. For this you need a left join, filtering for rows that don't join:
select
p.id,
p.name
from Players p
left join Wins w on w.Player_won = p.id
where w.Player_won is null
You can also use not in:
select
id,
name
from Players
where id not in (select Player_won from Wins)
How about the MINUS set operator?
Sample data:
SQL> with players (id, name) as
2 (select 1, 'Mick' from dual union all
3 select 2, 'Ffrank' from dual union all
4 select 3, 'Sarah' from dual union all
5 select 4, 'Eva' from dual union all
6 select 5, 'Joe' from dual
7 ),
8 wins (id, player_won) as
9 (select 1, 2 from dual union all
10 select 2, 1 from dual union all
11 select 3, 4 from dual union all
12 select 4, 5 from dual union all
13 select 5, 1 from dual
14 )
Query begins here:
15 select id from players
16 minus
17 select player_won from wins;
ID
----------
3
SQL>
So, yes ... player 3 didn't win any game so far.
I think you should provide your attempts next time, but here you go:
select p.name
from players p
where not exists (select * from wins w where p.id = w.player_won);
MINUS is not the best option here because of not using indexes and instead performing a full-scan of both tables.
I've a data base with two tables.
You don't show the names or any definition of the tables, leaving me to make an educated guess about their structure.
I tried but I don't know even how to begin.
What exactly did you try? Possibly what you are missing here is the concept of a LEFT OUTER JOIN.
Assuming the tables are named player_table and wins_table, and have column names exactly as you showed, and that the player_won column is intended to express the number of games won by the player of that row's ID, and without knowing whether or not wins_table will have rows for players with zero wins… this should cover it:
select Name
from players_table pt
left join wins_table wt on (pt.ID = wt.ID)
-- Either this player is explicitly specified to have Player_won=0
-- or there is no row for this player ID in the wins table
-- (but excluding the possibility of an explicit NULL value, since its meaning would be unclear)
where Player_won = 0 or wt.ID is null;
As you can see from the variety of answers you've gotten, there are many ways to accomplish this.
One additional way to do this is to use COUNT in a correlated subquery, as in:
SELECT *
FROM PLAYERS p
WHERE 0 = (SELECT COUNT(*)
FROM WINS w
WHERE w.PLAYER_WON = p.ID)
db<>fiddle here
SELECT *
FROM Players p
INNER JOIN Wins w
ON p.ID = w.ID
WHERE w.players_won = 0
I have not done SQL in awhile but I think this might be right if you are looking for players with 0 wins
I have a table with the following columns:
ID_group, ID_elements
For example with the following records:
1, 1
1, 2
2, 2
2, 4
2, 5
2, 6
3, 7
And I have sets of the elements, for example: 1,2,5; 1,5,2; 1,2,4; 2,7;
I need to check (true or false) that exist a common group for the pairs of adjacent elements.
For example elements:
1,2,5 -> true [i.e. elements 1,2 has common group 1 and elements 2,5 has common group 2]
1,5,2 -> false [i.e. 1,5 do not have a common group unlike 5,2 (but the result is false due to 1,5 - false)]
1,2,4 -> true
2,7 -> false
First, we need a list of pairs. We can get this by taking your set as an array, turning each element into a row with unnest and then making pairs by matching each row with its previous row using lag.
with nums as (
select *
from unnest(array[1,2,5]) i
)
select lag(i) over() a, i b
from nums
offset 1;
a | b
---+---
1 | 2
2 | 5
(2 rows)
Then we join each pair with each matching row. To avoid counting duplicate data rows twice, we count only the distinct rows.
with nums as (
select *
from unnest(array[1,2,5]) i
), pairs as (
select lag(i) over() a, i b
from nums
offset 1
)
select
count(distinct(id_group,id_elements)) = (select count(*) from pairs)
from pairs
join foo on foo.id_group = a and foo.id_elements = b;
This works on any size array.
dbfiddle
Your query to check if elements in a set evaluate to true or not can be done via procedures/function. Set representation can be taken as a string and then splitting it to substring then returning the required result can use a record for multiple entries. For sql query, below is a sample that can be used as a workaround, you can try changing the below query based on your requirement.
select case when ( Select count(*)
from ( SELECT
id_group, count(distinct id_elements)
from table where
id_group
in (1,2,5)
group by ID_group having
id_elements
in (1,2,5)) =3 ) then "true" else "false"
end) from table;
#Schwern, thank you, it helped. But I have changed the condition join foo on foo.id_group = a, because as I understand, a is element's ID, not group's. I have changed the following section:
join foo fA on fA.id_elements = a
join foo fB on fB.id_elements = b and fA.group_id = fB.group_id;
Apologies if this seems like a duplicate to this question but I believe my use case is slightly different.
I have two tables.
Table1
ID INTCODE
-----------------------------
000019827364 1
000019829201 2
890418392101 3
890418390395 4
890418398677 5
505586578932 6
505586578914 7
505586578933 8
505586578012 9
490201827383 10
490201827466 11
001952046578 12
Table2
INTCODE Category
-------------------------
1 Display
2 Display
3 Display
4 Display
5 Display
6 Audio
7 Audio
8 Audio
9 Audio
10 Audio
11 Audio
12 Audio
My expected query results are all possible 5 digit prefixes of each category and in each of these prefixes - I want to extract at least 2 full IDs. Below is an example if I had a where clause for category as 'Display'.
ID PREFIX Category ID
-----------------------------------------------
00001 Display 000019827364
00001 Display 000019829201
89041 Display 890418392101
89041 Display 890418390395
The query I currently have is
SELECT
SUBSTR(t1.ID, 1, 5)
FROM
table1 t1
,table2 t2
WHERE
AND UPPER(t2.category) = 'DISPLAY'
AND t2.REGION_ID = 1
AND t2.ZONE_ID = 2
AND t1.REGION_ID = 1
AND t1.ZONE_ID = 2
AND t1.INTCODE = t2.INTCODE
GROUP BY
SUBSTR(t1.ID, 1, 5)
I am now kind of lost. Should I be running another query where I say
t1.ID LIKE '00001%'
OR LIKE '89041%'
This list will go on to be huge cause some of the categories have 400-500 prefixes. Is there a better way to go about this? Possibly in a single query?
I'm using Oracle SQL.
Many thanks!
You can use row_number() for this:
select Category, ID, IDPrefix
from (select Category, ID, SUBSTR(ID, 1, 5) as IDPREFIX,
ROW_NUMBER() OVER (PARTITION BY SUBSTR(ID, 1, 5) ORDER BY ID) as seqnum
FROM table1 JOIN
table2 t2
ON t1.INTCODE = t2.INTCODE ANd
t1.Region_id = t2.Region_id and
t1.zone_id = t2.zone_id
WHERE UPPER(t2.category) = 'DISPLAY'
) t
WHERE seqnum <= 2;
Assuming you can to display two rows with different Id, without any more constraint, you could simply use an union where the first query would select the max id, and the second query the min id.
So your query would look something like this
select id_prefix, category, max(id)
from yourTable
union
select id_prefix, category, min(id)
from yourTable
Now simply add to this algorithm your where conditions.
I am dealing with a poorly designed database column which has values like this
ID cid Score
1 1 3 out of 3
2 1 1 out of 5
3 2 3 out of 6
4 3 7 out of 10
I want the aggregate sum and percentage of Score column grouped on cid like this
cid sum percentage
1 4 out of 8 50
2 3 out of 6 50
3 7 out of 10 70
How do I do this?
You can try this way :
select
t.cid
, cast(sum(s.a) as varchar(5)) +
' out of ' +
cast(sum(s.b) as varchar(5)) as sum
, ((cast(sum(s.a) as decimal))/sum(s.b))*100 as percentage
from MyTable t
inner join
(select
id
, cast(substring(score,0,2) as Int) a
, cast(substring(score,charindex('out of', score)+7,len(score)) as int) b
from MyTable
) s on s.id = t.id
group by t.cid
[SQLFiddle Demo]
Redesign the table, but on-the-fly as a CTE. Here's a solution that's not as short as you could make it, but that takes advantage of the handy SQL Server function PARSENAME. You may need to tweak the percentage calculation if you want to truncate rather than round, or if you want it to be a decimal value, not an int.
In this or most any solution, you have to count on the column values for Score to be in the very specific format you show. If you have the slightest doubt, you should run some other checks so you don't miss or misinterpret anything.
with
P(ID, cid, Score2Parse) as (
select
ID,
cid,
replace(Score,space(1),'.')
from scores
),
S(ID,cid,pts,tot) as (
select
ID,
cid,
cast(parsename(Score2Parse,4) as int),
cast(parsename(Score2Parse,1) as int)
from P
)
select
cid, cast(round(100e0*sum(pts)/sum(tot),0) as int) as percentage
from S
group by cid;