I have a table in SQL that is structured as follows:
Name Value1 Value2
A .2 .3
A .1 .05
A .5 .3
B .2 .4
B .1 .08
C .3 .4
C .2 .5
C .1 .3
How do I get all the Names where Value1 is less than Value2 for every row associated with a Name? In the example above, I would only want to pull out Name C.
I read this article: Select in MySQL where all rows meet a condition
but I don't think this applies to my problem, as this solution assumes you are comparing a row to fixed value.
A variant on some of the other answers, also using conditional aggregation:
SELECT Name
FROM yourTable
GROUP BY Name
HAVING SUM(CASE WHEN value1 >= value2 THEN 1 ELSE 0 END) = 0;
The above query asserts that each matching name group does not have any record for which value1 is greater than or equal to value2.
You can use group by and having:
select name
from t
group by name
having count(*) = sum(case when value1 < value2 then 1 else 0 end);
There are other ways to phrase this, such as:
select distinct name
from t
where not exists (select 1 from t t2 where t2.name = t.name and t2.value2 >= t2.value1);
Or:
select name
from t
except
select name
from t
where value2 >= value1;
You can get desired result with in clause
declare #table table (name varchar(10), value1 float, value2 float)
insert #table
select 'A', '0.2', '.3'
union all
select 'A' , '.1', '.05'
union all
select 'A', '.5', '.3'
union all
select 'B', '.2', '.4'
union all
select 'B', '.1' , '.08'
union all
select 'C', '.3' , '.4'
union all
select 'C', '.2' , '.5'
union all
select 'C' , '.1' , '.3'
Use In Clause where value1<value2
select * from #table where value1<value2
and name not in ( select name from #table where value1>value2)
You can use EXIST to check if the value exist in your desired condition wherein all rows by certain name have value2 greater than value1.
SELECT *
FROM TableName a
WHERE EXISTS (SELECT 1
FROM TableName b
WHERE a.name = b.Name
GROUP BY b.name
HAVING COUNT(case when b.value1 < b.value2 THEN 1 END) = COUNT(*))
Here's a Demo.
This will display all rows for the valid name. However, check other answer if you only want to display distinct name.
Related
I have a table of names and numeric values and I want to sum values grouped by names. This part is simple:
SELECT
name,
SUM(my_value) "MyValue"
FROM my_table
GROUP BY name
But I also have string 'UNLIMITED' in values. When there is 'UNLIMITED' in the group, I just want to select value 'UNLIMITED' and not do any sum. This is what I came up with using UNION but I know there is a better way:
SELECT
name,
MAX("MyValue")
FROM (
SELECT
name,
'UNLIMITED' "MyValue"
FROM my_table
WHERE my_value = 'UNLIMITED'
GROUP BY name
UNION
SELECT
name,
TO_CHAR(SUM(
CASE WHEN my_value = 'UNLIMITED'
THEN '0'
ELSE my_value END
)) "MyValue"
FROM my_table
GROUP BY name
) t
GROUP BY name
Please check SqlFiddle for real example.
Example table
NAME MY_VALUE
name1 50
name1 20
name2 30
name2 UNLIMITED
Example wanted result
NAME SUM("MYVALUE")
name1 70
name2 UNLIMITED
This is a pretty easy way to express the logic:
SELECT name,
(CASE WHEN MAX(my_value) = 'UNLIMITED' THEN 'UNLIMITED'
ELSE TO_CHAR(SUM(CASE WHEN my_value <> 'UNLIMITED' THEN my_value END))
END)
FROM my_table
GROUP BY name;
This uses the fact that characters are ordered after numbers.
Or similar logic:
SELECT name,
(CASE WHEN COUNT(*) <> COUNT(NULLIF(my_value, 'UNLIMITED')) THEN 'UNLIMITED'
ELSE TO_CHAR(SUM(NULLIF(my_value, 'UNLIMITED')))
END)
FROM my_table
GROUP BY name;
One way to do it with window functions.
SELECT DISTINCT
name,
CASE WHEN sum(case when my_value = 'UNLIMITED' then 1 else 0 end) over(partition by name) >= 1
THEN 'UNLIMITED'
ELSE cast(sum(case when my_value = 'UNLIMITED' then 0 else cast(my_value as number) end) over(partition by name)
as varchar(255))
end as myval
FROM my_table
This works
create table tempxx (a nvarchar2(10), b nvarchar2(20))
insert into tempxx values ('a', 50);
insert into tempxx values ('a', 20);
insert into tempxx values ('b', 30);
insert into tempxx values ('b', 'UNLIMITED');
SELECT allt.a, decode(ut.max, NULL, to_char(allt.sum), to_char(ut.max)) as val
From
((SELECT
a,
sum(decode(b, 'UNLIMITED', 0, b)) sum
FROM tempxx
Group by a) allT left join
(SELECT
a,
Max(b) max
FROM tempxx
WHERE b = 'UNLIMITED'
Group by a) ut on allt.a = ut.a)
A VAL
------------
b UNLIMITED
a 70
Basically, select all rows on left and join with only unlimited. If unlimited record is null, keep left one, otherwise take unlimited data
I have a weird grouping scenario and have some troubles finding out what would be the best way for grouping in SQL.
Imagine we have the following one table
CREATE TABLE Item
(
KeyId VARCHAR(1) NOT NULL,
Col1 INT NULL,
Col2 INT NULL,
Col3 INT NULL
)
GO
INSERT INTO Item (KeyId, Col1, Col2, Col3)
VALUES
('a',1,2,3),
('b',5,4,3),
('c',5,7,6),
('d',8,7,9),
('e',11,10,9),
('f',11,12,13),
('g',20,22,21),
('h',23,22,24)
I need to group records in this table so that if Col1 OR Col2 OR Col3 is the same for two records, then these two records should be in the same group, and there should be chaining.
In other words, with the data as above record 'a' (first record) has Col3 = 3 and record 'b' (second record) has also Col3 = 3, so these two should be in one group. But then record 'b' has the same Col1 as record 'c', so record 'c' should be in the same group as 'a' and 'b'. And then record 'd' has the same Col2 as in 'c', so this should also be in the same group. Similarly 'e' and 'f' has the same values in Col3 and Col1 respectively.
On the other hand records 'g' and 'h' will be in one group (because they have the same Col2 = 22), but this group will be different from the group for records 'a','b','c','d','e','f'.
The result of the query should be something like
KeyId GroupId
'a' 1
'b' 1
'c' 1
'd' 1
'e' 1
'f' 1
'g' 2
'h' 2
There is probably a way of doing this with some loops/cursors, but I started thinking about cleaner way and this seems quite difficult.
Here you go:
with g (rootid, previd, level, keyid, col1, col2, col3) as (
select keyid, '-', 1, keyid, col1, col2, col3 from item
union all
select g.rootid, g.keyid, g.level + 1, i.keyid, i.col1, i.col2, i.col3
from g
join item i on i.col1 = g.col1 or i.col2 = g.col2 or i.col3 = g.col3
where i.keyid > g.keyid
),
m (keyid, rootid) as (
select keyid, min(rootid) from g group by keyid
)
select * from m;
Result:
keyid rootid
----- ------
a a
b a
c a
d a
e a
f a
g g
h g
Note: Keep in mind that SQL Server has by default a limit of 100 iterations (number of rows per group) when processing recursive CTEs. In English: even though it's possible to do this as shown above, there are clear limitations to what SQL Server can process. If you reach this limit you'll get the message:
The maximum recursion 100 has been exhausted before statement completion.
If this happens consider adding the clause option (maxrecursion 32767).
I have a table Like this
Col1 | Col2
-----------
a | d
b | e
c | a
Now I want to create an statement to get an output like this:
First| Second
-------------------
a | Amsterdamm
b | Berlin
c | Canada
...
So far I have this consturct what is not working
SELECT *
FROM(
SELECT DISTINCT
CASE
when Col1 IS NULL then 'NA'
else Col1
END
FROM Table1
UNION
SELECT DISTINCT
CASE
when Col2 IS NULL then 'NA'
else Col2
END
FROM Table1
) AS First
,
(
SELECT DISTINCT
when First= 'a' then 'Amsterdam'
when First= 'b' then 'Berlin'
when First= 'c' then 'Canada'
) AS Second
;
can you help me with that
Sorry I have to edit my question to be more specific.
Not as familiar with DB2... I'll lookup if it has a concat function in a sec... and it does.
SELECT First, case when first = 'a' then
concat('This is a ',first)
case when first = 'b' then
concat('To Be or not to ',first)
case else
concat('This is a ',first) end as Second
FROM (
SELECT coalesce(col1, 'NA') as First
FROM Table
UNION
SELECT coalesce(col2, 'NA')
FROM table) SRC
WHERE first <> 'NA'
What this does is generate a single inline view called src with a column called first. If col1 or col2 of table are null then it substitutes NA for that value. It then concatenates first and the desired text excluding records with a first value of 'NA'
Or if you just create an inline table with the desired values and join in...
SELECT First, x.b as Second
FROM (
SELECT coalesce(col1, 'NA') as First
FROM Table
UNION
SELECT coalesce(col2, 'NA')
FROM table) SRC
INNER JOIN (select a,b
from (values ('a', 'This is a'),
('b', 'To B or not to' ),
('c', 'I like cat whose name starts with')) as x(a,b)) X;
on X.a = src.first
WHERE first <> 'NA'
Personally I find the 2nd option easier to read. Though if you have meaning for a,b,c I would think you'd want that stored in a table somewhere for additional access. In code seems like a bad place to store data like this that could change.
Assuming you want
a this is a a
b this is a b
c this is a c
d this is a d
e this is a e
thanks to xQbert
I could solve this problem like this
SELECT FirstRow, concat
(
CASE FirstRow
WHEN 'AN' then 'amerstdam'
WHEN 'G' then 'berlin'
ELSE 'NA'
END, ''
) AS SecondRow
FROM(
Select coalesce (Col1, 'NA') as FirstRow
FROM Table1
UNION
Select coalesce (Col2, 'NA')
FROM Table1) SRC
WHERE FirstRow <> 'NA'
;
I've a DB which stores a value from C to AAA, while C is the worst and AAA the best.
Now I need the average of this value and I don't know how to first convert the values into an int, calculate the average, round the average to an int and convert it back.
Definitions:
C = 1
B = 2
A = 3
AA = 4
AAA = 5
Is that even possible with an SQL statement? I tried to combine AVG and CASE, but I don't bring it to work...
Thanks for your help!
Regards,
select avg(case score
when 'C' then 1
when 'B' then 2
when 'A' then 3
when 'AA' then 4
when 'AAA' then 5
end) as avg_score
from the_table;
(this assumes that the column is called score)
To convert this back into the "character value", wrap the output in another case:
select case cast(avg_score as int)
when 1 then 'C'
when 2 then 'B'
when 3 then 'A'
when 4 then 'AA'
when 5 then 'AAA'
end as avg_score_value
from (
select avg(case score
when 'C' then 1
when 'B' then 2
when 'A' then 3
when 'AA' then 4
when 'AAA' then 5
end) as avg_score
from the_table;
) t
The above cast(avg_score as int) assumes ANSI SQL. Your DBMS might have different ways to cast a value to an integer.
I've created this example for u.
u can cast ur ranking into temp table, then calculate and when ur done, drop it.
create table sof (id int identity,a nvarchar (10))
insert into sof values ('a')
insert into sof values ('b')
insert into sof values ('c')
select case a when 'AAA ' then 5
when 'AA' then 4
when 'A' then 3
when 'B' then 2
else 1
end as av
into #temp
from sof
----for rounded
select ROUND(AVG(CAST(av AS FLOAT)), 4)
from #temp
--not rounded
select AVG (av)
from #temp
Given this:
with data_row as (select 1 as col_1 from dual)
select 'Y' as row_exists from dual where exists
(select null
from data_row
where col_1 in (2,1))
How can I get this?
Col_1 Row_exists
--------------------
1 Y
2 N
In order to get a row of output, you need a row of input. You want to get the second row with a "2", but there is no table with that value.
The approach is to generate a table that has the values that you want, and then use left outer join to find which match:
with data_row as (
select 1 as col_1
from dual
),
what_i_care_about as (
select 1 as col from dual union all
select 2 from dual
)
select wica.col,
(case when dr.col_1 is NULL then 'N' else 'Y' end) as row_exists
from what_i_care_about wica left outer join
data_row dr
on wica.col = dr.col_1;
You cannot do directly what you want -- which is to create a row for each missing value in the in list. If you have a lot of values and they are consecutive numeric, then you can use connect by or a recursive CTE to generate the values.