I have a table like this:
I am going to count the number of categories and how many rows are in each category.
I used this query:
But unfortunately apples is counted as separate category because it has "s" at the end.
I would recommend you look at some of the comments and restructure your data as I think it will cause you issues going forward but this query will do what you want but it isnt a nice one.
CTE for testing:
WITH fruit_table(Fruit, No_Fruit)
AS (
SELECT 'Apple', 3
UNION ALL
SELECT 'Apples', 2
UNION ALL
SELECT 'Orange', 1
UNION ALL
SELECT 'oranges', 2)
Query:
SELECT DISTINCT
LOWER(CASE
WHEN right(fruit, 1) = 's'
THEN left(fruit, -1)
ELSE fruit
END),
SUM(No_Fruit)
FROM fruit_table
GROUP BY LOWER(CASE
WHEN right(fruit, 1) = 's'
THEN left(fruit, -1)
ELSE Fruit
END);
There will be a more elegant way to get the results you want and a better solution would be to fix your schema but.... it works
Related
Say that I have the following table:
with data as (
select 'John' "name", 'A' "tag", 10 "count"
union all select 'John', 'B', 20
union all select 'Jane', 'A', 30
union all select 'Judith', 'A', 40
union all select 'Judith', 'B', 50
union all select 'Judith', 'C', 60
union all select 'Jason', 'D', 70
)
I know there are a number of distinct tag values, namely (A, B, C, D).
I would like to select the unique names that only have the tag A
I can get close by doing
-- wrong!
select
distinct("name")
from data
group by "name"
having count(distinct tag) = 1
however, this will include unique names that only have 1 distinct tag, regardless of what tag is it.
I am using PostgreSQL, although having more generic solutions would be great.
You're almost there - you already have groups with one tag, now just test if it is the tag you want:
select
distinct("name")
from data
group by "name"
having count(distinct tag) = 1 and max(tag)='A'
(Note max could be min as well - SQL just doesn't have single() aggregate function but that's different story.)
You can use not exists here:
select distinct "name"
from data d
where "tag" = 'A'
and not exists (
select * from data d2
where d2."name" = d."name" and d2."tag" != d."tag"
);
This is one possible way of solving it:
select
distinct("name")
from data
where "name" not in (
-- create list of names we want to exclude
select distinct name from data where "tag" != 'A'
)
But I don't know if it's the best or most efficient one.
I currently have a legacy table that looks like the one below.
This is a set of rules that our business has stored over the years. the issue is the "all" and "both" values really should be separated out into rows so they can be queried more efficiently.
For example, the contract length column can only ever be between 1 and 5, the type column can only ever be "gas" or "water" and the sales channel "internal" or "external". Instead of saying all or both, another row should exist with the specific rule and the table should look like the below.
So this will have a row for every variation in the first table.
I didn't think it would be a long task to manually do myself. but I was wrong :)
Does anyone have any idea on how to achieve this quickly in SQL? I would say what I have tried so far...but I am completely stumped on this one so am wondering if it can even be done at all?
This could be done in a single sql statement, but for the sake of your mental health and the ability to check interim result sets before you get to the final output is probably a lot healthier and less risky.
I would approach this with a UNION query, one set of UNIONs for each column that should be split out to more granular rows.
For instance for contractlength:
SELECT Supplier, 1, Type, SalesChannel FROM yourtable WHERE contractLength in ('1', 'All')
UNION ALL
SELECT Supplier, 2, Type, SalesChannel FROM yourtable WHERE contractLength in ('2', 'All')
UNION ALL
SELECT Supplier, 3, Type, SalesChannel FROM yourtable WHERE contractLength in ('3', 'All')
UNION ALL
SELECT Supplier, 4, Type, SalesChannel FROM yourtable WHERE contractLength in ('4', 'All')
UNION ALL
SELECT Supplier, 5, Type, SalesChannel FROM yourtable WHERE contractLength in ('5', 'All')
You can write those results out to a temp table, and then build your query for type on top of it writing to a new temp table.
SELECT Supplier, contractLength, 'Gas', SalesChannel FROM previousTempTable WHERE type in ('Gas','Both')
UNION ALL
SELECT Supplier, contractLength, 'Water', SalesChannel FROM previousTempTable WHERE type in ('Gas','Both')
Rinse and repeat for SalesChannel.
There's other more elegant ways to solve this with some SELECT DISTINCT and cross joins, but your list of values for each column is limited and this solution I'm proposing feels like a quick easy way to get your data in shape. It's also easy to understand if this is auditable data or the process needs to be repeated.
You don't need to query your table multiple times, or use temp tables. You can do this pretty elegantly with conditional unpivots, by using CROSS APPLY
SELECT
t.Supplier,
c1.ContractLength,
c2.Type,
c3.SalesChannel
FROM YourTable t
CROSS APPLY (
SELECT t.ContractLength
WHERE t.ContractLength <> 'All'
UNION ALL
SELECT *
FROM (VALUES
(1),(2),(3),(4),(5)
) v(ContractLength)
WHERE t.ContractLength = 'All'
) c1
CROSS APPLY (
SELECT t.Type
WHERE t.Type <> 'Both'
UNION ALL
SELECT *
FROM (VALUES
('Gas'),('Water')
) v(Type)
WHERE t.Type = 'Both'
) c2
CROSS APPLY (
SELECT t.SalesChannel
WHERE t.SalesChannel <> 'Both'
UNION ALL
SELECT *
FROM (VALUES
('Internal'),('External')
) v(SalesChannel)
WHERE t.SalesChannel = 'Both'
) c3;
A somewhat less efficient, but more compact, version of the same, is to use normal joins against the VALUES clauses
SELECT
t.Supplier,
c1.ContractLength,
c2.Type,
c3.SalesChannel
FROM YourTable t
JOIN (VALUES
(1),(2),(3),(4),(5)
) c1(ContractLength)
ON c1.ContractLength = t.ContractLength OR t.ContractLength = 'All'
JOIN (VALUES
('Gas'),('Water')
) c2(Type)
ON c2.Type = t.Type OR t.Type = 'Both'
JOIN (VALUES
('Internal'),('External')
) c3(SalesChannel)
ON c3.SalesChannel = t.SalesChannel OR t.SalesChannel = 'Both';
I am using WinSQL to run a query on a table to count the number of occurrences of literal strings. When trying to do a count on a specific set of strings, I still want to see if some values return a count of 0. For example:
select letter, count(*)
from table
where letter in ('A', 'B', 'C')
group by letter
Let's say we know that 'A' occurs 3 times, 'B' occurs 0 times, and 'C' occurs 5 times. I expect to have a table returned as such:
letter count
A 3
B 0
C 5
However, the table never returns a row with a 0 count, which results like so:
letter count
A 3
C 5
I've looked around and saw some articles mentioning the use of joins, but I've had no luck in correctly returning a table that looks like the first example.
You can create an in-line table containing all letters that you look for, then LEFT JOIN your table to it:
select t1.col, count(t2.letter)
from (
select 'A' AS col union all select 'B' union all select 'C'
) as t1
left join table as t2 on t1.col = t2.letter
group by t1.col
on many platforms you can now use the values statement instead of union all to create your "in line" table - like this
select t.letter, count(mytable.letter)
from ( values ('A'),('B'),('C') ) as t(letter)
left join mytable on t.letter = mytable.letter
group by t.letter
I'm not that familiar with WinSQL, but it's not pretty if you don't have the values that you want in the left most column in a table somewhere. If you did, you could use a left join and a conditional. Without it, you can do something like this:
SELECT all_letters.letter, IFNULL(letter_count.letter_count, 0)
FROM
(
SELECT 'A' AS letter
UNION
SELECT 'B' AS letter
UNION
SELECT 'C' AS letter
) all_letters
LEFT JOIN
(SELECT letter, count(*) AS letter_count
FROM table
WHERE letter IN ('A', 'B', 'C')
GROUP BY letter) letter_count
ON all_letters.letter = letter_count.letter
I have a script that extracts transactions and their details from a database. But my users complain that the file size being generated is too large, and so they asked for certain transactions to be just summed up/consolidated instead if they are of a certain classification, say Checking Accounts. That means there should only be one line in the result set named "Checking" which contains the sum of all transactions under Checking Accounts. Is there a way for an SQL script to go like:
CASE
WHEN Acct_class = 'Checking'
then sum(tran_amount)
ELSE tran_amount
END
I already have the proper GROUP BY and ORDER BY statements, but I can't seem to get my desired output. There is still more than one "Checking" line in the result set. Any ideas would be very much appreciated.
Try This,
Select sum(tran_amount) From tran_amount Where Acct_class = 'Checking'
You can try to achieve this using UNION ALL
SELECT tran_amount, .... FROM table WHERE NOT Acct_class = 'Checking'
UNION ALL
SELECT SUM(tran_amount), .... FROM table WHERE Acct_class = 'Checking' GROUP BY Acct_class, ...;
hi you can try below sql
select account_class,
case when account_class = 'saving' then listagg(trans_detail, ',') within group (order by emp_name) -- will give you all details transactions
when account_class = 'checking' then to_char(sum(trans_detail)) -- will give you only sum of transactions
end as trans_det from emp group by account_class;
Or, if your desired output is getting either the sum, either the actual column value based on another column value, the solution would be to use an analytical function to get the sum together with the actual value:
select
decode(acct_class, 'Checking', tran_amount_sum, tran_amount)
from (
select
sum(tran_amount) over (partition by acct_class) as tran_amount_sum,
tran_amount,
acct_class
from
YOUR_TABLE
)
You can try something like the following, by keeping single rows for some classes, and aggregating for some others:
with test (id, class, amount) as
(
select 1, 'a' , 100 from dual union all
select 2, 'a' , 100 from dual union all
select 3, 'Checking', 100 from dual union all
select 4, 'Checking', 100 from dual union all
select 5, 'c' , 100 from dual union all
select 6, 'c' , 100 from dual union all
select 7, 'c' , 100 from dual union all
select 8, 'd' , 100 from dual
)
select sum(amount), class
from test
group by case
when class = 'Checking' then null /* aggregates elements of class 'b' */
else id /* keeps elements of other classes not aggregated */
end,
class
This is my whole script
CREATE TABLE #TEST (
STATE CHAR(2))
INSERT INTO #TEST
SELECT 'ME' UNION ALL
SELECT 'ME' UNION ALL
SELECT 'ME' UNION ALL
SELECT 'SC' UNION ALL
SELECT 'NY' UNION ALL
SELECT 'SC' UNION ALL
SELECT 'NY' UNION ALL
SELECT 'SC'
SELECT *
FROM #TEST
ORDER BY CHARINDEX(STATE,'SC,NY')
I want to display all records start with SC first and second with NY and then rest come without any order.
When I execute the above sql then first all records come with ME which is not in my order by list.
Tell me where I am making the mistake. Thanks.
Use CASE statement
SELECT *
FROM #TEST
ORDER BY CASE WHEN STATE LIKE 'SC%' THEN 0
WHEN STATE LIKE 'NY%' THEN 1
ELSE 2
END
Output
STATE
-----
SC
SC
SC
NY
NY
ME
ME
ME
See here for what CHARINDEX returns when your search pattern is Not found.
- https://msdn.microsoft.com/en-GB/library/ms186323.aspx
To avoid dealing with the 0 case, you could use the below.
ORDER BY
CASE LEFT(state, 2)
WHEN 'SC' THEN 1
WHEN 'NY' THEN 2
ELSE 3
END
This should be easier to write, read and maintain.
It should also use less CPU, though I doubt it will make a tangible difference.
CASE/IIF with LIKE is one way to do it . You can also alter your CHARINDEX like this to get what you want.The Problem in your case is that in ascending order, no match records are shown first as 0 is returned for such records. You can Reverse for criteria to 'NY,SC' and do a DESC order.
Query
SELECT *
FROM #TEST
ORDER BY CHARINDEX(STATE,'NY,SC') DESC,State
Output
SC
SC
SC
NY
NY
ME
ME
ME