REGEXP to validate a specific number - sql

Question

How can I search for a specific number in an array using REGEXP?
I have an array and need to verify if it has a specific number.
Ex: [5,2,1,4,6,19] and I am looking for number 1, but just the number 1 and not any number that contain the digit 1.
I had to do this:
case when REGEXP_INSTR(JSON_QUERY(MY_JSON_COLUMN,'$.path') , '[[]{1}[1][,]')<>0
or REGEXP_INSTR(JSON_QUERY(MY_JSON_COLUMN,'$.path') , '[,]{1}[1][,]{1}')<>0
or REGEXP_INSTR(JSON_QUERY(MY_JSON_COLUMN,'$.path') , '[,]{1}[1][]]')<>0
or REGEXP_INSTR(JSON_QUERY(MY_JSON_COLUMN,'$.path') , '[[]{1}[1][]]') <>0
then 'DIGIT_ONE' else 'NO_DIGIT_ONE'
end
Is there anything simpler?

Answer 1

You can use
(^|\D)1(\D|$)
This will seach for 1 not enclosed with other digits.
See this regex demo.
Details
(^|\D) - start of string or non-digit
1 - a 1 char
(\D|$) - non-digit or end of string.

Answer 2

Do NOT use regular expressions, use a proper JSON parser and then filter for the number you want:
SELECT my_json_column,
CASE
WHEN JSON_EXISTS( my_json_column, '$?(#.path[*] == 1)' )
THEN 'DIGIT ONE'
ELSE 'NO DIGIT ONE'
END AS has_one
FROM table_name;
or (if you are using Oracle 12.1 and cannot use path filter expressions with JSON_EXISTS, which is only available from Oracle 12.2):
SELECT my_json_column,
CASE
WHEN EXISTS(
SELECT 'X'
FROM JSON_TABLE(
t.my_json_column,
'$.path[*]'
COLUMNS (
value NUMBER PATH '$'
)
)
WHERE value = 1
)
THEN 'DIGIT ONE'
ELSE 'NO DIGIT ONE'
END
FROM table_name t;
Which, for the sample data:
CREATE TABLE table_name (
my_json_column CHECK ( my_json_column IS JSON )
) AS
SELECT '{"path":[5,2,1,4,6,19],"not_this_path":[1,2,3,4,5]}' FROM DUAL UNION ALL
SELECT '{"path":[5,2,4,6,19],"not_this_path":[1,2,3,4,5]}' FROM DUAL UNION ALL
SELECT '{"path":[11],"not_this_path":[1]}' FROM DUAL UNION ALL
SELECT '{"path":[2],"not_this_path":[1]}' FROM DUAL UNION ALL
SELECT '{"path":[1,11]}' FROM DUAL;
Both output:
MY_JSON_COLUMN | HAS_ONE
:-------------------------------------------------- | :-----------
{"path":[5,2,1,4,6,19],"not_this_path":[1,2,3,4,5]} | DIGIT ONE
{"path":[5,2,4,6,19],"not_this_path":[1,2,3,4,5]} | NO DIGIT ONE
{"path":[11],"not_this_path":[1]} | NO DIGIT ONE
{"path":[2],"not_this_path":[1]} | NO DIGIT ONE
{"path":[1,11]} | DIGIT ONE
db<>fiddle here

Answer 3

Alternatively, with a little bit more typing (a little bit? Am I kidding?!), splitting the string into rows and comparing values to the search string:
SQL> with test (col) as
2 (select '[5,2,1,4,6,19]' from dual)
3 select t.col,
4 case when '&par_search_string' in
5 (select regexp_substr(substr(col, 2, length(col) - 1), '[^,]+', 1, level) val
6 from test
7 connect by level <= regexp_count(col, ',') + 1
8 )
9 then 'Search string exists'
10 else 'Search string does not exist'
11 end result
12 from test t;
Enter value for par_search_string: 1
COL RESULT
-------------- ----------------------------
[5,2,1,4,6,19] Search string exists
SQL> /
Enter value for par_search_string: 24
COL RESULT
-------------- ----------------------------
[5,2,1,4,6,19] Search string does not exist
SQL>