Is it possible to return substring of column by char in python sqllite?

Question

I have a table holding strings with multiple "." sections.

eg,

"field1.field2.field3"
"field1.field2.field4"
"field1.field2.field5"
"field1.field2.field6"
"field40.field50.field60"

I would to query the table and return a distinct list of items up until the last ".".

In the above example the query should return

"field1.field2"
"field40.field50"

I am aware of SELECT DISTINCT , INSTR and SUBSTR but how do I combine all in the same query?

Answer 1

SQLite has very poor string functionality. One method that almost gets you there is:

select rtrim(col, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234456789')

You can then get what you want by doing:

select substr(col, 1, length(rtrim(lower(col), 'abcdefghijklmnopqrstuvwxyz01234456789')) - 1)