问题
I want to compare the values of two columns (diff table) having comma separated values of two different Oracle tables. I want to find rows that match with all values (NAME1 all values should match with NAME2 values).
Note: The comma separated values are in different order.
Example:
T1:
ID_T1 NAME1
===================================
1 ASCORBIC ACID, PARACETAMOL, POTASSIUM HYDROGEN CARBONATE
2 SODIUM HYDROGEN CARBONATE, SODIUM CARBONATE ANHYDROUS, CITRIC ACID
3 CAFFEINE, PARACETAMOL PH. EUR.
4 PSEUDOEPHEDRINE HYDROCHLORIDE,DEXCHLORPHENIRAMINE MALEATE
T2:
ID_T2 NAME2
=================================
4 POTASSIUM HYDROGEN CARBONATE, ASCORBIC ACID, PARACETAMOL
5 SODIUM HYDROGEN CARBONATE, SODIUM CARBONATE ANHYDROUS
6 PARACETAMOL PH. EUR.,CAFFEINE
7 CODEINE PHOSPHATE, PARACETAMOL DC
8 DEXCHLORPHENIRAMINE MALEATE, DEXTROMETHORPHAN HYDROBROMIDE
10 DEXCHLORPHENIRAMINE MALEATE, PSEUDOEPHEDRINE HYDROCHLORIDE
MY RESULT should only show the matching row based on ALL NAME Matches in both tables.
ID_T1 ID_T2 MATCHING NAME
==================================
1 4 POTASSIUM HYDROGEN CARBONATE, ASCORBIC ACID, PARACETAMOL
3 6 PARACETAMOL PH. EUR.,CAFFEINE
4 10 PSEUDOEPHEDRINE HYDROCHLORIDE,DEXCHLORPHENIRAMINE MALEATE
Tried with REGEXP_SUBST but wasn't able to make it work.
I used the below code to parse the values:
SELECT REGEXP_SUBSTR (NAME1, '[^,]+', 1, ROWNUM)
FROM T1
CONNECT BY ROWNUM <= LENGTH (NAME1) -
LENGTH (REPLACE (NAME, ',')) + 1
回答1:
You could get the table(s) into first normal form and then compare the compounds that are stored in each row. A starting point could be:
{1} Tokenize each row, and write the tokens into a new table. Give each token its original ID plus a 3-letter prefix, indicating which table the token came from. {2} Group the rows of the new ("normalized") table by ID, and perform a LISTAGG(). Perform a self join, and find matching "token groups".
{1} Tokenize, create table as select (CTAS)
create table tokens
as
select
ltrim( -- ltrim() and rtrim() remove leading/trailing spaces (blanks)
rtrim(
substr( N.wrapped
, instr( N.wrapped, ',', 1, T.pos ) + 1
, ( instr( N.wrapped, ',', 1, T.pos + 1 ) - instr( N.wrapped, ',', 1, T.pos ) ) - 1
)
)
) token
, N.id
from (
select ',' || name1 || ',' as wrapped, 'T1_' || to_char( id_t1 ) as id from t1 -- names wrapped in commas, (table)_id
union all
select ',' || name2 || ',' , 'T2_' || to_char( id_t2 ) from t2
) N join (
select level as pos -- (max) possible position of char in an existing token
from dual
connect by level <= (
select greatest( -- find the longest string ie max position (query T1 and T2)
( select max( length( name1 ) ) from t1 )
, ( select max( length( name2 ) ) from t2 )
) as pos
from dual
)
) T
on T.pos <= ( length( N.wrapped ) - length( replace( N.wrapped, ',') ) ) - 1
;
The inspiration to tokenize without using CONNECT BY came from this SO answer.
The contents of the TOKENS table will look something like this:
SQL> select * from tokens ;
TOKEN ID
ASCORBIC ACID T1_1
SODIUM HYDROGEN CARBONATE T1_2
CAFFEINE T1_3
PSEUDOEPHEDRINE HYDROCHLORIDE T1_4
PARACETAMOL T1_100
sodium hydroxide T1_110
POTASSIUM HYDROGEN CARBONATE T2_4
SODIUM HYDROGEN CARBONATE T2_5
PARACETAMOL PH. EUR. T2_6
CODEINE PHOSPHATE T2_7
DEXCHLORPHENIRAMINE MALEATE T2_8
DEXCHLORPHENIRAMINE MALEATE T2_10
PARACETAMOL T2_200
...
{2} GROUP BY, LISTAGG, self join
select
S1.id id1
, S2.id id2
, S1.tokengroup_T1
, S2.tokengroup_T2
from
(
select substr( id, 4, length( id ) - 3 ) id
, listagg( token, ' + ' ) within group ( order by token ) tokengroup_T1
from tokens
group by id
having substr( id, 1, 3 ) = 'T1_'
) S1
join
(
select substr( id, 4, length( id ) - 3 ) id
, listagg( token, ' + ' ) within group ( order by token ) tokengroup_T2
from tokens
group by id
having substr( id, 1, 3 ) = 'T2_'
) S2
on S1.tokengroup_T1 = S2.tokengroup_T2
;
-- result
ID1 ID2 TOKENGROUP_T1 TOKENGROUP_T2
4 10 DEXCHLORPHENIRAMINE MALEATE + PSEUDOEPHEDRINE HYDROCHLORIDE DEXCHLORPHENIRAMINE MALEATE + PSEUDOEPHEDRINE HYDROCHLORIDE
110 210 potassium carbonate + sodium hydroxide potassium carbonate + sodium hydroxide
1 4 ASCORBIC ACID + PARACETAMOL + POTASSIUM HYDROGEN CARBONATE ASCORBIC ACID + PARACETAMOL + POTASSIUM HYDROGEN CARBONATE
3 6 CAFFEINE + PARACETAMOL PH. EUR. CAFFEINE + PARACETAMOL PH. EUR.
When doing things this way, you can get the substances into (alphabetical) order, and you can also pick a "delimiter" that you like (we have used '+') here.
ALTERNATIVE
If all that is no use to you, or you think this is too complicated, then you could try using TRANSLATE(). In this case, I'd recommend stripping all spaces/blanks from your dataset (in a query - not altering the original data!) like so:
Query
select
id1, id2
, name1, name2
from (
select
id_t1 id1
, id_t2 id2
, T1.name1 name1
, T2.name2 name2
from T1
join T2
on translate( replace( T1.name1, ' ', '' ), replace( T2.name2, ' ', '' ), '!' )
= translate( replace( T2.name2, ' ', '' ), replace( T1.name1, ' ', '' ), '!' )
) ;
Result
ID1 ID2 NAME1 NAME2
2 5 SODIUM HYDROGEN CARBONATE, SODIUM CARBONATE ANHYDROUS, CITRIC ACID SODIUM HYDROGEN CARBONATE, SODIUM CARBONATE ANHYDROUS
3 6 CAFFEINE, PARACETAMOL PH. EUR. PARACETAMOL PH. EUR.,CAFFEINE
100 10 PARACETAMOL, DEXTROMETHORPHAN, PSEUDOEPHEDRINE, PYRILAMINE DEXCHLORPHENIRAMINE MALEATE, PSEUDOEPHEDRINE HYDROCHLORIDE
110 210 sodium hydroxide, potassium carbonate sodium hydroxide, potassium carbonate
NOTE: I've added the following rows to your sample data:
-- T1
110, 'sodium hydroxide, potassium carbonate'
-- T2
210, 'sodium hydroxide, potassium carbonate'
211, 'potassium hydroxide, sodium carbonate'
I found that it is easy to use TRANSLATE() in a way that gives you "false positives" ie the substances with ids 110, 210, and 211 will appear to "match". (In other words: I don't think this is the right tool for this job.)
DBFIDDLE here
(follow the link to see the sample tables and queries).
来源：https://stackoverflow.com/questions/58237799/comparing-comma-separated-values-from-two-columns-of-two-different-tables