如何将Oracle Sql转换为Postgresql

Question

My SQL query has "connect by regexp_substr". How do I convert it to PostgreSQL 10 query ?

I have tried this in Ubuntu and toad...

  select regexp_substr('1,2,4','[^,]+', 1, level) from dual
    connect by regexp_substr('1,2,4', '[^,]+', 1, level) is not null;

How to do I get convert above query to PostgreSQL version 10?

Answer 1

string_to_array() is typically faster if no regular expression is needed.

select *
from unnest(string_to_array('1,2,4', ',')) as t(c);

Answer 2

If I understand correctly, you want to split a comma-delimited string into rows. For that, use regexp_split_to_table() :

select regexp_split_to_table('1,2,4', ',')

In Postgres, it is possible that you would really phrase the overall query using arrays. If you have a question about a larger query, ask in a new question.