Thread: Difference between LIKE and %

Originally Posted by geek_guest

what is the difference between if i use substr (last_name,-1,1)='n'; or last_name is like'_n' or '%n' for the all the names in last_name which end by letter 'n' question asked by visitor rajesh

substr(char,m [,n])
purpose: returns a portion of char, beginning at character m, n characters
long. If m is positive, oracle counts from the beginning of char to
find the first character. If m is negative, oracle counts backwards
from the end of char. The value m cannot be 0. If n is omitted,
oracle returns all characters to the end of char. The value n
cannot be less than 1.
examples:
select substr('abcdefg',3,2) "substring" from dual
substring
cd
select substr('abcdefg',-3,2) "reversed substring" from dual
reversed substring
ef
LIKE
The like condition allows you to use wildcards in the where clause of an sql statement. This allows you to perform pattern matching. The like condition can be used in any valid sql statement - select, insert, update, or delete.
the patterns that you can choose from are:
% allows you to match any string of any length (including zero length)
_ allows you to match on a single character
select * from emp where ename like '_n' return records form emp where second char in ename starts with 'n'
select * from emp where ename like '%n' return records from emp where ename ends with 'n'