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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 have an apex item P_USERS which can have a value higher than the amount of rows returning from the query below.
I have a classic report which has the following query:
select
first_name,
last_name
from accounts
where account_role = 'Author'
order by account_nr;
I want placeholder rows to be added to the query (first_name = null, last_name = null etc.), if the total rows from the query is lesser than the value in the apex_item P_USERS.
Any tips on how to achieve this? Maybe with a LEFT join?
If you have more result than the minima you defined, you must add the rest with union.
Here is what you could try to adapt to your case:
SELECT i,c FROM (
select rownum i, c from (
select 'a' c from dual union all select 'b' from dual union all select 'd' from dual union all select 'be' from dual
)), (Select Rownum r From dual Connect By Rownum <= 3)
where (i(+)= r)
union select i,c from (select rownum i, c from (
select 'a' c from dual union all select 'b' from dual union all select 'd' from dual union all select 'be' from dual
)) where i>3
You may try to use a LEFT JOIN.
First, create a list of number until the limit you want like suggested here:
-- let's say you want 300 records
Select Rownum r From dual Connect By Rownum <= 300
Then you can use this to left join and have empty records:
SELECT C, R FROM
( select rownum i, c from (select 'a' c from dual union all select 'b' from dual) )
, ( Select Rownum r From dual Connect By Rownum <= 300)
where i(+)= r order by r
The above gives you an ordered list starting with 'a', 'b', then null until the end.
So you could adapt it to your case so:
SELECT F,L FROM
( select rownum i, f, l from (
select first_name f, last_name l
from accounts where account_role = 'Author'
order by account_nr) )
, ( Select Rownum r From dual Connect By Rownum <= 300)
where i(+)= r
The below SQL conceptually replicates the problem I'm trying to solve. Despite passing a NOT IN clause all three records are returned.
SELECT * FROM (
SELECT 'JACK' AS VALUE FROM DUAL
UNION
SELECT 'JOHN' AS VALUE FROM DUAL
UNION
SELECT 'BOB' AS VALUE FROM DUAL
) WHERE VALUE NOT IN (SELECT 'BOB,JOHN' FROM DUAL);
I have a table that holds a delimited string that I want to use as the criteria to exclude records from the dataset. However, the problem I have is that the returned string is not broken down into its delimited items. I want the above to translate to:
SELECT * FROM (
SELECT 'JACK' AS VALUE FROM DUAL
UNION
SELECT 'JOHN' AS VALUE FROM DUAL
UNION
SELECT 'BOB' AS VALUE FROM DUAL
) WHERE VALUE NOT IN ('BOB','JOHN');
You can use regexp_substr for that problem:
SELECT * FROM (
SELECT 'JACK' AS VALUE FROM DUAL
UNION
SELECT 'JOHN' AS VALUE FROM DUAL
UNION
SELECT 'BOB' AS VALUE FROM DUAL
)
WHERE VALUE NOT IN (SELECT regexp_substr('BOB,JOHN','[^,]+', 1, LEVEL) FROM dual CONNECT BY regexp_substr('BOB,JOHN', '[^,]+', 1, LEVEL) IS NOT NULL)
'BOB,JOHN' is not a list of two string values it is one string value that just happens to contain a comma in the string and:
'JACK' = 'BOB,JOHN'
'JOHN' = 'BOB,JOHN'
'BOB' = 'BOB,JOHN'
Are all false so your query will return all rows as matched by the NOT IN filter.
You can surround your values and list with the delimiter characters and test whether the value is not a sub-string of the list like this:
SELECT *
FROM (
SELECT 'JACK' AS VALUE FROM DUAL UNION ALL
SELECT 'JOHN' AS VALUE FROM DUAL UNION ALL
SELECT 'BOB' AS VALUE FROM DUAL
)
WHERE INSTR( ',' || 'BOB,JOHN' || ',', ',' || value || ',' ) = 0
Or you can use a user-defined collection:
CREATE OR REPLACE TYPE stringlist IS TABLE OF VARCHAR2(20);
Then use the MEMBER OF operator to test whether a value is a member of the collection:
SELECT *
FROM (
SELECT 'JACK' AS VALUE FROM DUAL UNION ALL
SELECT 'JOHN' AS VALUE FROM DUAL UNION ALL
SELECT 'BOB' AS VALUE FROM DUAL
)
WHERE VALUE NOT MEMBER OF StringList( 'BOB', 'JOHN' );
With Oracle 11g I want to parse a number to strip decimals if their value is 0 and keep two decimal figure after the decimal separator ',' if the value of decimals is different from 0
Example:
1,00 -> 1
1,001 -> 1
0,203 -> 0,20
And so on.
I've obtained something like that in a very unelegant way
select replace(trim(to_char (trunc ('0,2345',2),'9999999990.99')), '.', ',')
from dual
Do you know more elegant way? The output should be a char (not number).
Not sure it's much more elegant, but assuming your replace is to deal with different locales, this might work for you:
with t as (
select 1.00 as n from dual
union all select 1.001 from dual
union all select 0.203 from dual
union all select 0.2345 from dual
union all select 112.999 from dual
)
select n, regexp_replace(to_char(trunc(n, 2), '9999999990D00',
'NLS_NUMERIC_CHARACTERS='',.'''), '[,.]00$', null) as new_n
from t;
N NEW_N
---------- --------------
1 1
1.001 1
0.203 0,20
0.2345 0,23
112.999 112,99
The nls_param argument to to_char let's you dictate whether it used a comma or a period as the decimal separator. If you can set that at session level then the query looks a bit simpler. The regexp_replace strips ,00 (or .00, which come to think of it is overkill) from the end of th string.
As ThinkJet noted the regexp_replace is a bit excessive, and since the decimal seperator is defined in the column clase (and the format has no group separators anyway) it can be done with a plan replace:
with t as (
select 1.00 as n from dual
union all select 1.001 from dual
union all select 0.203 from dual
union all select 0.2345 from dual
union all select 112.999 from dual
union all select 13.08 from dual
)
select n, replace(trim(
to_char(trunc(n, 2), '9999999990D00', 'NLS_NUMERIC_CHARACTERS='',.''')),
',00', null) as new_n
from t;
N NEW_N
---------- --------------
1 1
1.001 1
0.203 0,20
0.2345 0,23
112.999 112,99
13.08 13,08
Still not sure this can be described as 'elegant' though.
To achieve correct results you must deal with numbers, not strings:
with t as (
select 1.00 as n from dual
union all select 1.001 from dual
union all select 0.203 from dual
union all select 0.2345 from dual
union all select 112.999 from dual
union all select 112.105 from dual
union all select 0 from dual
union all select -12.307 from dual
)
select
n,
decode( trunc(n,2) - trunc(n) ,
0, to_char(trunc(n), 'TM9', 'NLS_NUMERIC_CHARACTERS = '', '''),
to_char(trunc(n,2),'9999999990D00', 'NLS_NUMERIC_CHARACTERS = '', ''')
)
string_val
from t
SQLFiddle
P.S. Updated to get incorrect truncation instead of round, as in OP request.
Another variant
SELECT n,
to_char( trunc( n, 2 ),
case when mod( trunc( n, 2 ), 1 ) = 0
then '9990'
else '9990D00'
end, 'NLS_NUMERIC_CHARACTERS='',.''' ) val
from t
;
SQLFiddle demo
SELECT TO_NUMBER('*') FROM DUAL
This obviously gives me an exception:
ORA-01722: invalid number
Is there a way to "skip" it and get 0 or NULL instead?
The whole issue: I have NVARCHAR2 field, which contains numbers and not almost ;-) (like *) and I need to select the biggest number from the column.
Yes, I know it is a terrible design, but this is what I need now... :-S
UPD:
For myself I've solved this issue with
COALESCE(TO_NUMBER(REGEXP_SUBSTR(field, '^\d+')), 0)
From Oracle Database 12c Release 2 you could use TO_NUMBER with DEFAULT ... ON CONVERSION ERROR:
SELECT TO_NUMBER('*' DEFAULT 0 ON CONVERSION ERROR) AS "Value"
FROM DUAL;
Or CAST:
SELECT CAST('*' AS NUMBER DEFAULT 0 ON CONVERSION ERROR) AS "Value"
FROM DUAL;
db<>fiddle demo
COALESCE(TO_NUMBER(REGEXP_SUBSTR(field, '^\d+(\.\d+)?')), 0)
will also get numbers with scale > 0 (digits to the right of the decimal point).
I couldn't find anything better than this:
function safe_to_number(p varchar2) return number is
v number;
begin
v := to_number(p);
return v;
exception when others then return 0;
end;
select COALESCE(TO_NUMBER(REGEXP_SUBSTR( field, '^(-|+)?\d+(\.|,)?(\d+)?$')), 0) from dual;
It will convert 123 to 123, but 123a or 12a3 to 0.
Fitting the original question and rather old skool
select a, decode(trim(translate(b,'0123456789.',' ')),null,to_number(b),0) from
(
select '1' a, 'not a number' b from dual
union
select '2' a, '1234' b from dual
)
It's probably a bit messy rolling your own regexp to test for a number, but the code below might work. I think the other solution by Gabe involving a user defined function is more robust since you are using the built in Oracle functionality (and my regexp is probably not 100% correct) but it might be worth a go:
with my_sample_data as (
select '12345' as mynum from dual union all
select '54-3' as mynum from dual union all
select '123.4567' as mynum from dual union all
select '.34567' as mynum from dual union all
select '-0.3462' as mynum from dual union all
select '0.34.62' as mynum from dual union all
select '1243.64' as mynum from dual
)
select
mynum,
case when regexp_like(mynum, '^-?\d+(\.\d+)?$')
then to_number(mynum) end as is_num
from my_sample_data
This will then give the following output:
MYNUM IS_NUM
-------- ----------
12345 12345
54-3
123.4567 123.4567
.34567
-0.3462 -0.3462
0.34.62
1243.64 1243.64
select DECODE(trim(TRANSLATE(replace(replace(A, ' '), ',', '.'), '0123456789.-', ' ')),
null,
DECODE(INSTR(replace(replace(A, ' '), ',', '.'), '.', INSTR(replace(replace(A, ' '), ',', '.'), '.') + 1),
0,
DECODE(INSTR(replace(replace(A, ' '), ',', '.'), '-', 2),
0,
TO_NUMBER(replace(replace(A, ' '), ',', '.'))))) A
from (select '-1.1' A from DUAL union all select '-1-1' A from DUAL union all select ',1' A from DUAL union all select '1..1' A from DUAL) A;
This code excludes such strings as: -1-1, 1..1, 12-2 and so on. And I haven't used regular expressions here.
A combination of previous solutions (from #sOliver and #Mike Meyers) and trying to grab as much numbers as possible by removing the last '$' from REGEXP.
It can be used to filter the actual number from a configuration table, and have a "kind-of" comment next to the number as '12 Days'.
with my_sample_data as (
select '12345' as mynum from dual union all
select '123.4567' as mynum from dual union all
select '-0.3462' as mynum from dual union all
select '.34567' as mynum from dual union all
select '-.1234' as mynum from dual union all
select '**' as mynum from dual union all
select '0.34.62' as mynum from dual union all
select '24Days' as mynum from dual union all
select '42ab' as mynum from dual union all
select '54-3' as mynum from dual
)
SELECT mynum,
COALESCE( TO_NUMBER( REGEXP_SUBSTR( mynum, '^(-|+)?\d*(.|,)?(\d+)?') ) , 0) is_num
FROM my_sample_data;
would give
MYNUM IS_NUM
-------- ----------
12345 12345
123.4567 123.4567
-0.3462 -0.3462
.34567 0.34567
-.1234 -0.1234
** 0
0.34.62 0.34
24Days 24
42ab 42
54-3 54
Best method seems to be the function solution but if you don't have necessary privileges in the environment you are struggling (like me), then you can try this one:
SELECT
CASE
WHEN
INSTR(TRANSLATE('123O0',
' qwertyuıopğüasdfghjklşizxcvbnmöçQWERTYUIOPĞÜASDFGHJKLŞİZXCVBNMÖÇ~*\/(){}&%^#$<>;#€|:_=',
'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
),
'X') > 0
THEN 'Y'
ELSE 'N'
END is_nonnumeric
FROM DUAL
By the way: In my case the problem was due to "," and "." :) So take that into consider. Inspired from this one. Also this one seems more concise.
By the way 2: Dear Oracle, can you please create some built-in functions for such small but invaluable needs?