我想了解如何在 BigQuery 中使用 REGEXP_EXTRACT 函数

Question

I have a column string value:

SELFSERVE TICKET\STATION\TRAINCOMPANY\GBR

I would like to extract the part of the string before the first "\\" ie SELFSERVE TICKET

What would be the right syntax to achieve this? If there are better functions to use I am ears.

Answer 1

I don't think that a regex is necessary here. You can just use regular string functions:

substr(mycol, 1, strpos(mycol, '\') - 1)

This gives you everything before the first \\ .

If you have strings that do not contain \\ at all, and you want to return the entire string in that case:

substr(concat(mycol, '\'), 1, strpos(mycol, '\') - 1)

Finally, if you want to get all parts at once, you can use split() , which returns an array of strings:

split(mycol, '\')

Answer 2

在 BigQuery 中，我会使用：

select split(col, '\')[ordinal(1)] as first_value