How to convert a date format YYYY-MM-DD into integer YYYYMMDD in Presto/Hive?

Also you can use date_format function:

hive> select cast(date_format('2017-07-01','yyyyMMdd') as int);
OK
20170701

If you just need to transform your date YYYY-MM-DD into an integer YYYYMMDD why don't you try to first remove all the occurrences of "-" from the string representation of your date before casting the result to int by using something like this?

cast(regexp_replace(str_column,'-','') as int)

Simply REPLACE the '-' with Empty string and CAST it into INT.

Try the following:

SELECT CAST(REPLACE(Date_Column,'-','') AS INT)