PostgreSQL将字符串匹配为动态输入的字符串

Question

I have a varchar field in my database table A let's call it store_name, this field gets its value from entity A, now entity B enters store_name into a different database table B now I want to get all records in table A where the store_name matches the values in table B.

How would you recommend me doing the query as I don't control the values of those 2 fields?

What do you think about PostgreSQL fuzzystrmatch? The tables contain thousands of records.

Thanks

Answer 1

Assuming that both table A and table B are in the same database. And I guess since you don't control insertion of data, you are not sure if the values are of same case or there may be a spelling mismatch.

Case 1: If the problem is only of case-mismatch, you can use ilike :

Select a.store_name
from a, b
Where a.store_name ilike b.store_name

Case 2: If you also want to check for spelling mismatch, but words sound similar, then after installing postgresql-contrib package and creating extension fuzzystrmatch, you can use:

Select a.store_name
from a, b
Where a.store_name ilike b.store_name OR
soundex(a.store_name) = soundex(b.store_name)

If you are dealing with names, which may not always be in English, it may be more appropriate to use metaphone or dmetaphone function instead of soundex.

Documentation: Fuzzystrmatch

Answer 2

If you want matching you can use a straight up join.

Select a.store_name
from a 
     join b on a.store_name = b.store_name; 

If you want to use fuzzy matching just use the various functions available in the join criteria. Documentation here

Note: there are some limitations to Fuzzy string matching so i would advise testing each out on values that you either know match or don't.