意外に説明が充実してる。
hive> DESCRIBE FUNCTION EXTENDED substr;
OK
substr(str, pos[, len]) - returns the substring of str that starts at pos and is
of length len
pos is a 1-based index. If pos<0 the starting position is determined by counting
backwards from the end of str.
Example:
> SELECT substr('Facebook', 5) FROM src LIMIT 1;
'book'
> SELECT substr('Facebook', -5) FROM src LIMIT 1;
'ebook'
> SELECT substr('Facebook', 5, 1) FROM src LIMIT 1;
'b'
Time taken: 0.156 seconds
hive>
