Trim leading zeroes if it is numeric and not trim zeroes if it is alphanumeric - sql

Question

In a column, there are numeric and alphanumeric values starting with '0'.
How to trim leading zeroes if it is numeric and should not trim zeroes if it is alphanumeric in Oracle.
I need to use it in WHERE Condition.
Ex.
000012345 should be 12345.
012321 should be 12321.
00012JY12 should be 00012JY12.
This is what I tried:
SELECT COUNT(*)
FROM <TABLE 1> ONN, <TABLE 2> SV
WHERE SV.CSA_SHP_VISIT_STG_SEQ_ID=ONN.CSA_SHOP_VIST_SEQ_ID
AND EXISTS (SELECT '1' FROM <TABLE 3> TMP
WHERE TRIM(SV.WORK_ORDER_NUM) = TRIM(TMP.WORK_ORDER_NUM)
AND PLANT IN ('EMA')
AND regexp_replace(TRIM(ONN.INSTLD_PART), '^0+([[:digit:]]+)$',
'\1')=TRIM(TMP.INSTLD_PART) AND
TRIM(ONN.INSTLD_PART_SERIAL_NUM)=TRIM(TMP.INSTLD_PART_SERIAL_NUM) AND
nvl(to_number(TRIM(ONN.INSTLD_PART_CSN)),0)=
nvl(to_number(TRIM(TMP.INSTLD_PART_CSN)),0)
and REGEXP_LIKE(tmp.INSTLD_PART_CSN, '^-?\d+(\.\d+)?$'))

Answer 1

Whenever possible (in this case it is), use standard string functions, such as SUBSTR, INSTR, TRANSLATE, etc. instead of regular expression functions. Regular expressions are much more powerful, but also much more time consuming (precisely for that reason), so they should be used only when really needed.
If the column name is str, then:
case when translate(str, 'z0123456789', 'z') is null
then ltrim(str, '0')
else str end
TRANSLATE will translate z to itself, all the digits to NULL, and all other characters to themselves. (Alas, the z, or SOME non-digit character, is needed.)
The input is all-digits if and only if the result of TRANSLATE is NULL.
Demo:
select str, case when translate(str, 'z0123456789', 'z') is null
then ltrim(str, '0')
else str
end as new_str
from
(
select '000012345' as str from dual union all
select '012321' as str from dual union all
select '00012JY12' as str from dual
);
STR NEW_STR
--------- ---------
000012345 12345
012321 12321
00012JY12 00012JY12

Answer 2

Use regexp_replace(col, '^0+([[:digit:]]+)$', '\1').
This replaces strings that only consist of leading zeros and trailing digits with the trailing digits alone, thus removing the zeros.
Sample query:
select col, regexp_replace(col, '^0+([[:digit:]]+)$', '\1') as newvalue
from
(
select '000012345' as col from dual
union all
select '012321' as col from dual
union all
select '00012JY12' as col from dual
);
Result:
COL | NEWVALUE
----------+----------
000012345 | 12345
012321 | 12321
00012JY12 | 00012JY12

Answer 3

If you are using Oracle 12.2, you could use the error handling of the CAST expression.
https://docs.oracle.com/en/database/oracle/oracle-database/12.2/sqlrf/CAST.html#GUID-5A70235E-1209-4281-8521-B94497AAEF75
Along that:
CASE WHEN CAST(<expression> AS NUMERIC DEFAULT NULL ON CONVERSION ERROR) IS NULL
THEN <expression>
ELSE TRIM(LEADING '0' FROM <expression>)
END
Replace <expression> with your column name (or whatever). I'm using null as magic value in the default null on conversion error clause but this does no harm as null input will then just match the THEN clause and pass the null through.

Answer 4

You can create a function that check if it is numeric or not, see this link for the function sample,
check if "it's a number" function in Oracle
You can TRIM the zeros of numeric value just by adding 0 to it,
Sample code:
--get the IS_NUMERIC function from the link
SELECT DECODE(IS_NUMERIC(col1), 'Y', col1+0, 'N', col1)
FROM your_table;