How substr works on dates - oracle

I am trying to understand a query in my application where it uses substr function.
I have gone through the documentation for substr, which looks simple and clear.
Now below is my query without using substr:
select last_day(to_date(to_char(add_months(TO_DATE('2004/10/25', 'yyyy/mm/dd'),1),'YYYY')||'0201','YYYYMMDD')) from dual;
This gives me result as 2/29/2004. The above query just returns last day of Feb in simple words.
Now I am using substr as below:
select substr(last_day(to_date(to_char(add_months(TO_DATE('2004/10/25', 'yyyy/mm/dd'),1),'YYYY')||'0201','YYYYMMDD')),5,1) from dual;
So here the start value is 5 & length is 1, so I am expecting output as 2 looking at 2/29/2004. but the actual output is E, I am not clear from where this E is coming as result.

You cannot use SUBSTR() on DATE values. SUBSTR() works only on strings!
When you run SUBSTR({DATE_VALUE}, ...) then Oracle actually does following:
SELECT
SUBSTR(
TO_CHAR(
{DATE_VALUE}, (SELECT VALUE FROM nls_session_parameters WHERE parameter = 'NLS_DATE_FORMAT')
), ...
)
FROM dual;
What is the purpose of this query? Do you like to find out whether input year is a leap-year?

Try this instead -
select substr(to_char(last_day(to_date(to_char(add_months(TO_DATE('2004/10/25', 'yyyy/mm/dd'),1),'YYYY')||'0201','YYYYMMDD')),'dd/mm/yyyy'),5,1)
from dual;

Related

Having issue with extracing date from CLOB data

Hi I am having issue when extracting fields from CLOB data. For one record I am not getting desired output.
The record is as below:
{1:F014243107336}{2:O2021216200422XXX24563}{3:{108:O2020}{121:2c02a452-5}{433:HIT}}{4:
:4A:SEC:20200901
:4B:FC5253
:4C:20042000,
:4D:XXXXXXX
:4E:RXX
:4F:RXXXX
-}{5:{CHK:87D1003B01F7}{TNG:}}{S:{SAC:}{COP:S}}<APSECSIGN>FS3sfasdfg!==</APSECSIGN>?
I want to extract data from tag :4A: into REF_NUMBER.
I am using below SQL to get the data.
NVL(TRIM(TRANSLATE(REGEXP_REPLACE(REGEXP_SUBSTR(dbms_lob.substr(CLOB, 4000, 1 ), ':4A.?:[^:]+(:|-\})'), ':20.?:([^:]+)(:|-\})', '\1'),CHR(10)||CHR(13), ' ')),' ') AS REF_NUMBER
the output I am getting is "SEC". However I want to see output as SEC:20200901.
Can any one suggest what I am missing in my query or provide me correct query.
A general suggestion. Why don't you have your data stored as JSON ? Because, JSON related functions are very fast when compared to others. And then your problem becomes quite easy.
However to answer your question:
with inputs (str) as
(
select to_clob(q'<
{1:F014243107336}{2:O2021216200422XXX24563}{3:{108:O2020}{121:2c02a452-5}{433:HIT}}{4:
:4A:SEC:20200901
:4B:FC5253
:4C:20042000,
:4D:XXXXXXX
:4E:RXX
:4F:RXXXX
-}{5:{CHK:87D1003B01F7}{TNG:}}{S:{SAC:}{COP:S}}<APSECSIGN>FS3sfasdfg!==</APSECSIGN>?
>') from dual
)
select str, regexp_substr(str,'SEC:\d+',1,1,'n') as val
from inputs;
Output:
Updated
If you know the date is always going to be 8 digits after the :4A: tag, you can use REGEXP_SUBSTR to get the value you need. Combining it with DBMS_LOB.SUBSTR removes the tag and converts it to a string.
SELECT DBMS_LOB.SUBSTR ((REGEXP_SUBSTR (clob_val, ':4A:.*\d{8}')), 4000, 5)
FROM (SELECT EMPTY_CLOB ()
|| '{1:F014243107336}{2:O2021216200422XXX24563}{3:{108:O2020}{121:2c02a452-5}{433:HIT}}{4:
:4A:SEC:20200901
:4B:FC5253
:4C:20042000,
:4D:XXXXXXX
:4E:RXX
:4F:RXXXX
-}{5:{CHK:87D1003B01F7}{TNG:}}{S:{SAC:}{COP:S}}<APSECSIGN>FS3sfasdfg!==</APSECSIGN>?' AS clob_val
FROM DUAL);

Convert String to Date field for SQL Oracle

I need to convert a string to a date field. The field stores 30 characters. Dates, when present, are formatted as 'yyyymmdd' (20170202). In all cases, dates have 22 spaces after. I need to format this field as a date field like this: dd-mm-yyyy.
I've tried several formulas:
TO_CHAR(PERSACTION.NEW_VALUE_02, 'dd-mm-yyyy') ,TO_CHAR(PERSACTION.NEW_VALUE_02, 'yyyymmdd'), trim(TO_CHAR(PERSACTION.NEW_VALUE_02, 'yyyymmdd')) with error message: invalid number format model. Your expertise is welcome and appreciated.
to_char(to_date( rtrim(new_value_02), 'yyyymmdd'), 'dd-mm-yyyy')
Should do the trick. rtrim removes spaces on right side of string. Then I convert it to date using the date format specified, and then convert it to a string again in the desired format.
Did tried to convert to date format and then to char again?
TO_CHAR(TO_DATE(PERSACTION.NEW_VALUE_02,'yyyymmdd'),'dd-mm-yyyy')
Please, please, please do not store DATEs and CHARACTER datatypes. This will only lead to issues that can be avoided when using the DATE datatype.
If you want to change the string 20170202 to another string and not actually a date (which would have no intrinsic formatted text representation), you could optionally use a regular expression to transform it, instead of converting to a date and back:
select regexp_replace('20170202 ', '^(\d{4})(\d{2})(\d{2}) +$', '\3-\2-\1')
from dual;
REGEXP_REPLACE(
---------------
02-02-2017
Or you could use substr instead of regexp_substr, which may perform better even if you have to call it three times; using a CTE just to avoid repeating the value:
with t(str) as (
select '20170202 ' from dual
)
select substr(str, 7, 2) ||'-'|| substr(str, 5, 2) ||'-'|| substr(str, 1, 4)
from t;
SUBSTR(STR
----------
02-02-2017
If you do convert to a date and back you would uncover any values which cannot be converted, as they will cause an exception to be thrown. That would imply you have bad data; which would have been avoided by using the right data type in the first place, of course. These will convert any old rubbish, with varying results depending on how far the strings stray from the pattern you expect - but including strings like '20170231' which represent an invalid date. And null value or strings of just spaces will be converted to odd things with the substr version, but you could filter those out.
You can see the kind of variation you would get with some sample data that doesn't match your expectations:
with t(str) as (
select '20170202 ' from dual
union all select '20170231 ' from dual
union all select '2017020c ' from dual
union all select '2017020 ' from dual
union all select '201702021 ' from dual
union all select ' ' from dual
union all select null from dual
)
select str,
regexp_replace(str, '^(\d{4})(\d{2})(\d{2}) +$', '\3-\2-\1') as reg,
substr(str, 7, 2) ||'-'|| substr(str, 5, 2) ||'-'|| substr(str, 1, 4) as sub
from t;
STR REG SUB
------------- ------------- -------------
20170202 02-02-2017 02-02-2017
20170231 31-02-2017 31-02-2017
2017020c 2017020c 0c-02-2017
2017020 2017020 0 -02-2017
201702021 201702021 02-02-2017
- -
--
With the anchors and whitespace expectation, the regular expression doesn't modify anything that doesn't consist entirely of 8 numeric characters. But it can still form invalid 'dates'.

Oracle invalid number in clause

I'm struggling with getting a query to work, and I could really use some help. We have an in house app that we use for building small web apps where I work. It's basically a drag and drop GUI. There's functionality built in to access query string values using the key.
I'm passing a comma separated list of values into a page through the query string. I'm then trying to use the list of values as part of an in clause in a query.
I can see that the value is correct in the query string.
orders=1,2,3
Here's the specific part of the query
"AND OrderNumber IN (this is where it maps from the query string)
I've tried running similar queries in Toad, and I think I've found the issue. It's giving an invalid number error, and I think it's wrapping the query string value in single quotes. I can replicate the error when I do "AND OrderNumber IN ('1,2,3')" in Toad.
Here's where I get really confused. The following works in Toad.
"AND OrderNumber IN ('1','2','3')"
So I tried recreating that by doing
select replace('1,2,3', ',', chr(39)||','||chr(39)) from dual;
I have confirmed that returns '1','2','3' in Toad.
However, I still get an Invalid Number error when I run the following in Toad.
AND OrderNumber IN (replace('1,2,3', ',', chr(39)||','||chr(39))
I've been racking my brain over this, and I can't figure it out. It seems to me that if "AND OrderNumber IN ('1','2','3')" works, and replace('1,2,3', ',', chr(39)||','||chr(39)) returns '1','2','3', that "AND OrderNumber IN (replace('1,2,3', ',', chr(39)||','||chr(39))" should work.
Any help you might be able to offer on this would be greatly appreciated. I know the rest of the query works. That's why I didn't post it. I'm just stuck on trying to get this IN clause working.
A change to phonetic_man's answer that will allow for NULL elements in the list. The regex format of '[^,]+' for parsing delimited lists does not handle NULL list elements and will return an incorrect value if one exists and thus its use should be avoided. Change the original by deleting the number 2 for instance and see the results. You will get a '3' in the 2nd element's position! Here's a way that handles the NULL and returns the correct value for the element:
SELECT TRIM(REGEXP_SUBSTR(str, '(.*?)(,|$)', 1, LEVEL, NULL, 1)) str
FROM ( SELECT '1,,3,4' str FROM dual )
connect by level <= regexp_count(str, ',') + 1;
See here for more info and proof: https://stackoverflow.com/a/31464699/2543416
Can you try the following query.
SELECT * FROM orders
WHERE orderno IN
(
SELECT TRIM(REGEXP_SUBSTR(str, '[^,]+', 1, LEVEL)) str
FROM ( SELECT '1,2,3,4' str FROM dual )
CONNECT BY INSTR(str, ',', 1, LEVEL - 1) > 0
)
The inline query splitting the string in different rows. So, on executing it you will get the following result.
SELECT trim(regexp_substr(str, '[^,]+', 1, LEVEL)) str
FROM ( SELECT '1,2,3,4' str FROM dual )
CONNECT BY instr(str, ',', 1, LEVEL - 1) > 0
1
2
3
4
Now, passing this result to the main query IN clause should work.
I think the desired clause to be built is:
AND OrderNumber IN (1,2,3)
A numeric list. The example you tested:
AND OrderNumber IN ('1','2','3')
works because an implicit conversion from a VARCHAR2 to a NUMBER is occurring for each element in the list.
The following clause will not work because no implicit conversion of the string '1,2,3' can be made (note the clause has a single string element):
AND OrderNumber IN ('1,2,3')
When doing a replace, you are converting the single string: 1,2,3 with the single string: 1','2','3 and this single string cannot be implicitly converted to a number.

trim value till specified string in oracle pl/sql

i want to trim value of the given string till specified string in oracle pl/sql.
some thing like below.
OyeBuddy$$flex-Flex_Image_Rotator-1443680885520.
In the above string i want to trim till $$ so that i will get "flex-Flex_Image_Rotator-1443680885520".
You can use different ways; here are two methods, with and without regexp:
with test(string) as ( select 'OyeBuddy$$flex-Flex_Image_Rotator-1443680885520.' from dual)
select regexp_replace(string, '(.*)(\$\$)(.*)', '\3')
from test
union all
select substr(string, instr(string, '$$') + length('$$'))
from test
You want to do a SUBSTR where the starting position is going to be the position of '$$' + 2 . +2 is because the string '$$' is of length 2, and we don't want to include that string in the result.
Something like -
SELECT SUBSTR (
'ABCDEF$$some_big_text',
INSTR ('ABCDEF$$some_big_text', '$$') + 2)
FROM DUAL;

Oracle statement

Tables records as below
D:\HOME\DOC\FILE\2001\12\TT-12S2Q99-EE-EE1.pdf
D:\HOME\DOC\FILE\2002\02\TT-12S2Q94-EE-EE1.xml
D:\HOME\DOC\FILE\2005\05\TT-12S2Q98-EE-EE1.pdf
D:\HOME\DOCS\TEMPFILE\TT-12S2Q88-EE-EE1.pdf
I want to extract those file names only. The result should be
TT-12S2Q99-EE-EE1
TT-12S2Q94-EE-EE1
TT-12S2Q98-EE-EE1
TT-12S2Q88-EE-EE1
Anyone can give me a hand ?
You can use INSTR with the third parameter negative to search backwards in the string from the end (something I didn't know you could do until a few minutes ago). Combine that with a SUBSTR and you should have what you want:
SQL> select filename from mytable;
FILENAME
--------------------------------------------------------------------------------
C:\path\to\some\file.txt
SQL> select substr(filename, instr(filename, '\', -1) + 1) from mytable;
SUBSTR(FILENAME,INSTR(FILENAME,'\',-1)+1)
--------------------------------------------------------------------------------
file.txt
Take a look at the SUBSTR and INSTR functions.
If you're still stuck after that, post your best attempt at what you've done.

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