PostgreSQL SUBSTRING
From w3cyberlearnings
Contents |
Postgresql substring
This function extracts substring from a string. It can be used the POSIX regular expression matching. Please check the example.
Syntax substring
- string is the string
- start is the location to start extract
- length is the length of the string to extract.
substring(string start length); OR substring(string from pattern for escape)
Example 1
test2=# SELECT substring('lovely' from 5 for 2);
substring
-----------
ly
(1 row)
Example 2:regular expression
test2=# SELECT substring('great' from '...$');
substring
-----------
eat
(1 row)
test2=# SELECT substring('great' from '^..');
substring
-----------
gr
(1 row)
Example 3
test2=# SELECT user_firstname,
test2-# substring(user_firstname from 1 for 1)
test2-# FROM profile;
user_firstname | substring
----------------+-----------
Jim | J
king | k
Jammi | J
Bob | B
|
(5 rows)
