Can some one please help me in writing a sql query that should do a oracle min function based on the following conditions.
For eg for column values
0,0,0,0 then output should be 0
0,null,0,null then output should be o
0,2,4,5,6 then output should be 2 (Note that we are excluding Zero here)
0,2,null,4,5 then output should be 2 (same here we are excluding zero)
null,null,null, null then output should be null.
I wrote query already that satisfies all the above cases but failing for last case when all the column values are null. Instead of returning null it is returning 0. Can some one modify the below query to fit for the last case as well?
select NVL(MIN(NULLIF(columnname,0)),0) from tablename;
Please also keep in mind that the query should be runnable in oracle as well as hsqldb as we are using hsql db for running junits.
If all 4 cases satisfied by your query then just a case will solve your problem.
SELECT CASE WHEN MIN(COLUMNNAME) IS NULL THEN NULL ELSE NVL(MIN(NULLIF(COLUMNNAME,0)),0) END FROM TABLENAME;
Note:- assuming all the cases satisfied by your query except 5th.
I will show below an input table with two columns, ID and VAL, to illustrate the various possibilities. You want a single result per ID (or even for the entire table), so this must be a job for GROUP BY and some aggregate function. You want to distinguish between three types of values: Greater than zero, zero, and null (in this order); you want to pick the "highest priority group" that exists for each ID (in this order of priority), and for that priority group only, you want to pick the min value. This is exactly what the aggregate FIRST/LAST function does. To order by the three "classes" of values, we use a CASE expression in the ORDER BY clause of the aggregate LAST function.
The WITH clause below is not part of the solution - I only include it to create test data (in your real life situation, use your actual table and column names and remove the entire WITH clause).
with
inputs ( id, val ) as (
select 1, 0 from dual union all
select 1, 0 from dual union all
select 1, 0 from dual union all
select 2, 0 from dual union all
select 2, null from dual union all
select 2, 0 from dual union all
select 3, 0 from dual union all
select 3, 2 from dual union all
select 3, 5 from dual union all
select 4, 0 from dual union all
select 4, 3 from dual union all
select 4, null from dual union all
select 5, null from dual union all
select 5, null from dual
)
select id,
min(val) keep (dense_rank last order by case when val > 0 then 2
when val = 0 then 1
else 0
end
) as min_val
from inputs
group by id
order by id
;
ID MIN_VAL
---------- ----------
1 0
2 0
3 2
4 3
5
Related
I am trying to generate a random value from a list of valid values [1,2,3,4,5,9]. If I run my function 10 times, there are 2 values that never appear. I need every value in the list to be present in my sample. How can I ensure this ? An equal distribution would be good, but at least few rows of every value.
select random_code
from (
with temp_code_table as (
select '1' as random_code from dual union
select '2' as random_code from dual union
select '3' as random_code from dual union
select '4' as random_code from dual union
select '5' as random_code from dual union
select '9' as random_code from dual)
select random_code from temp_code_table order by dbms_random.value)
where rownum = 1;
I am running the above SQL inside a function, which checks that the random code generated is not the same as the original value.
Edit: Not sure the answer in the below post will help me achieve what I want.
Generating Random Value using CASE
Any advice on how to achieve this ?
"A random number" and "at least one of each" cannot be combined. The definition of random is that you down't know what you'll get... Roll a dice 10 times. Are you sure you'll have thrown all sides at least once ? No.
So to solve your problem, you can select one of each first - that way you have those already and then fill up the rest with randomly selected numbers from the set.
with temp_code_table (nr) as
(
SELECT '1' FROM dual UNION
SELECT '2' FROM dual UNION
SELECT '3' FROM dual UNION
SELECT '4' FROM dual UNION
SELECT '5' FROM dual UNION
SELECT '9' FROM dual
)
-- now select one of each. order doesn't matter, we're doing that at the end
, one_of_each AS
(
SELECT nr FROM temp_code_table
)
-- ok we got at least one of each. Now fill up the rest with randoms
-- generate a list of hundred random values 1,2,3,4,5,9 (100 is chosen randomly)
, hundred_random AS
(
SELECT CASE round(dbms_random.value(1,6))
WHEN 1 THEN '1'
WHEN 2 THEN '2'
WHEN 3 THEN '3'
WHEN 4 THEN '4'
WHEN 5 THEN '5'
WHEN 6 THEN '9'
END AS nr
FROM DUAL connect by LEVEL < 101
)
-- select 4 out of those.
, four_more (nr) AS
(
SELECT nr FROM hundred_random WHERE rownum < 5
)
-- put it all together
, ten_rows AS
(
SELECT nr FROM one_of_each
UNION ALL
SELECT nr FROM four_more
)
-- and shuffle...
SELECT nr FROM ten_rows order by dbms_random.value
;
The "temp_code_table" cte generates exactly 6 rows. That way you have at least one of each number in the set.
The "hundred_random" cte uses the case statement on the random number which will generate a single random value of the set. Then that is run 100 times using CONNECT BY LEVEL. Out of those 100, 4 are picked. Those 4 could all be 1 - this is random, there is no guarantee that you have distinct numbers.
At the end we union the 6 rows of the temp_code_table cte and the 4 rows of the four_more and order them randomly.
I have a problem in SQL Oracle, I'm trying to create a view that contains values with letters and numbers and I want to sort them in a specific order.
Here is my query:
create or replace view table1_val (val, msg_text) as
select
val, msg_text
from
table_val
where
val in ('L1','L2','L3','L4','L5','L6','L7','L8','L9','L10','L11','L12','L13','L14','G1','G2','G3','G4')
order by lpad(val, 3);
The values are displayed like this:
G1,G2,G3,G4,L1,L2,L3,L4,L5,L6,L7,L8,L9,L10,L11,L12,L13
The thing is that I want to display the L values first and then the G values like in the where condition. The 'val' column is VARCHAR2(3 CHAR). The msg_text column is irrelevant. Can someone help me with that? I use Oracle 12C.
You must interpret the second part of the val column as a number
order by
case when val like 'L%' then 0 else 1 end,
to_number(substr(val,2))
This work fine for your current data, but may fail in future if a new record is added with non-numeric structure.
More conservative (and more hard to write), but safe would be to used a decode for all the current keys, ordering unknown keys on the last position (id = 18 in the example):
order by
decode(
'L1',1,
'L2',2,
'L3',3,
'L4',4,
'L5',5,
'L6',6,
'L7',7,
'L8',8,
'L9',9,
'L10',10,
'L11',11,
'L12',12,
'L13',13,
'G1',14,
'G2',15,
'G3',16,
'G4',17,18)
You can't do anything based on the order of the WHERE condition
But you can use a CASE on the ORDER BY
ORDER BY CASE
WHEN SUBSTR(val, 1, 1) = 'L' THEN 1
WHEN SUBSTR(val, 1, 1) = 'G' THEN 2
ELSE 3
END,
TO_NUMBER (SUBSTR(val, 2, 10));
Another option to consider might be using regular expressions, such as
SQL> with table1_val (val) as
2 (select 'L1' from dual union all
3 select 'L26' from dual union all
4 select 'L3' from dual union all
5 select 'L21' from dual union all
6 select 'L11' from dual union all
7 select 'L4' from dual union all
8 select 'G88' from dual union all
9 select 'G10' from dual union all
10 select 'G2' from dual
11 )
12 select val
13 from table1_val
14 order by regexp_substr(val, '^[[:alpha:]]+') desc,
15 to_number(regexp_substr(val, '\d+$'));
VAL
---
L1
L3
L4
L11
L21
L26
G2
G10
G88
9 rows selected.
SQL>
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
Is it possible to keep order from a 'IN' conditional clause?
I found this question on SO but in his example the OP have already a sorted 'IN' clause.
My case is different, 'IN' clause is in random order
Something like this :
SELECT SomeField,OtherField
FROM TestResult
WHERE TestResult.SomeField IN (45,2,445,12,789)
I would like to retrieve results in (45,2,445,12,789) order. I'm using an Oracle database. Maybe there is an attribute in SQL I can use with the conditional clause to specify to keep order of the clause.
There will be no reliable ordering unless you use an ORDER BY clause ..
SELECT SomeField,OtherField
FROM TestResult
WHERE TestResult.SomeField IN (45,2,445,12,789)
order by case TestResult.SomeField
when 45 then 1
when 2 then 2
when 445 then 3
...
end
You could split the query into 5 queries union all'd together though ...
SELECT SomeField,OtherField
FROM TestResult
WHERE TestResult.SomeField = 4
union all
SELECT SomeField,OtherField
FROM TestResult
WHERE TestResult.SomeField = 2
union all
...
I'd trust the former method more, and it would probably perform much better.
Decode function comes handy in this case instead of case expressions:
SELECT SomeField,OtherField
FROM TestResult
WHERE TestResult.SomeField IN (45,2,445,12,789)
ORDER BY DECODE(SomeField, 45,1, 2,2, 445,3, 12,4, 789,5)
Note that value,position pairs (e.g. 445,3) are kept together for readability reasons.
Try this:
SELECT T.SomeField,T.OtherField
FROM TestResult T
JOIN
(
SELECT 1 as Id, 45 as Val FROM dual UNION ALL
SELECT 2, 2 FROM dual UNION ALL
SELECT 3, 445 FROM dual UNION ALL
SELECT 4, 12 FROM dual UNION ALL
SELECT 5, 789 FROM dual
) I
ON T.SomeField = I.Val
ORDER BY I.Id
There is an alternative that uses string functions:
with const as (select ',45,2,445,12,789,' as vals)
select tr.*
from TestResult tr cross join const
where instr(const.vals, ','||cast(tr.somefield as varchar(255))||',') > 0
order by instr(const.vals, ','||cast(tr.somefield as varchar(255))||',')
I offer this because you might find it easier to maintain a string of values rather than an intermediate table.
I was able to do this in my application using (using SQL Server 2016)
select ItemID, iName
from Items
where ItemID in (13,11,12,1)
order by CHARINDEX(' ' + Convert("varchar",ItemID) + ' ',' 13 , 11 , 12 , 1 ')
I used a code-side regex to replace \b (word boundary) with a space. Something like...
var mylist = "13,11,12,1";
var spacedlist = replace(mylist,/\b/," ");
Importantly, because I can in my scenario, I cache the result until the next time the related items are updated, so that the query is only run at item creation/modification, rather than with each item viewing, helping to minimize any performance hit.
Pass the values in via a collection (SYS.ODCINUMBERLIST is an example of a built-in collection) and then order the rows by the collection's order:
SELECT t.SomeField,
t.OtherField
FROM TestResult t
INNER JOIN (
SELECT ROWNUM AS rn,
COLUMN_VALUE AS value
FROM TABLE(SYS.ODCINUMBERLIST(45,2,445,12,789))
) i
ON t.somefield = i.value
ORDER BY rn
Then, for the sample data:
CREATE TABLE TestResult ( somefield, otherfield ) AS
SELECT 2, 'A' FROM DUAL UNION ALL
SELECT 5, 'B' FROM DUAL UNION ALL
SELECT 12, 'C' FROM DUAL UNION ALL
SELECT 37, 'D' FROM DUAL UNION ALL
SELECT 45, 'E' FROM DUAL UNION ALL
SELECT 100, 'F' FROM DUAL UNION ALL
SELECT 445, 'G' FROM DUAL UNION ALL
SELECT 789, 'H' FROM DUAL UNION ALL
SELECT 999, 'I' FROM DUAL;
The output is:
SOMEFIELD
OTHERFIELD
45
E
2
A
445
G
12
C
789
H
fiddle
I am using the following query :
select 8 Union Select 0 Union Select 15
to populate the these 3 number in a column. The result I get is:
0
8
15
But I want 8 to come first and then 0 and then 15, e.g.
8
0
15
How do I do this?
Use UNION ALL
E.g.
select 8 UNION ALL Select 0 UNION ALL Select 15
#SimonMartin's answer works for the exact data set you give, but be aware that if your data set contains duplicate values, the UNION ALL will produce different results than UNION.
The UNION operator removes duplicates, whereas the UNION ALL will preserve them (as well as their order, as noted in #SimonMartin's answer).
If you want to combine the functionality of your UNION operator with the ordering capabilities provided by UNION ALL, then you need to start with UNION ALL then filter out the duplicate values yourself:
-- baseline query + 1 duplicate record at the end
with query as
(
select 8 as Val
UNION ALL
Select 0 as Val
UNION ALL
Select 15 as Val
UNION ALL
Select 0 as Val
)
-- now add row numbers
, queryWithRowNumbers as
(
select row_number() over (order by (select 0)) as rn, Val
from query
)
-- finally, get rid of the duplicates
select Val from (
select Val, min(rn) as minRn
from querywithrownumbers
group by val
) q
order by minRn
This will give results of
8
0
15
whereas if you ONLY use UNION ALL you will end up with
8
0
15
0