如何在 Django 中的 sql 的分隔符之后检索 substring？

Question

How to retrieve a substring after a delimiter from sql in Django?

For example, I have "2021-22:32" saved in my sql database. I wish to run a query which returns "32", ie substring after the delimiter ':'.

How can I do that in Django?

Say my model is

class model(models.Model):
    str=models.CharField(max_length=25)

Suggest a query which returns all the entities, but with str values as explained above.

Answer 1

In pure Python, you have the following options:

inp = "2021-22:32"
output = inp.split(':')[1]         # 32
output = re.sub(r'^.*:', '', inp)  # 32

On the SQL side, you could use similar options, depending on what your particular database vendor actually is. For instance, on Postgres you have the SPLIT_PART function available:

SELECT SPLIT_PART('2021-22:32', ':', 2);  -- 32