This will be used to extract substrings.
Syntax: substr (string,
start_chr_count [, no_of_chars])
Ex:
SQL> select
substr('computer',2), substr('computer',2,5), substr('computer',3,7)
from dual;
SUBSTR( SUBST SUBSTR
---------- ------- --------
omputer omput mputer
Ø If no_of_chars parameter is negative then
it will display nothing.
Ø If both
parameters except string are null or
zeros then it will display nothing.
Ø If no_of_chars parameter is greater than
the length of the string then it ignores and calculates based on the orginal
string length.
Ø If start_chr_count is negative then it will
extract the substring from right end.
1 2 3 4 5 6 7 8
C O M P U T E R
-8 -7 -6 -5 -4 -3 -2 -1
