I have a bind in the SQL query
SELECT * FROM users WHERE name LIKE '%?%'
the bind set the ?.
Now, if i want to search with like method everything work but if, without change the sql, i want to search the exact match i dont now how to do.
I tried some regexp int the textbox es:
_jon \jon\ [jon] and some others but nothing work properly.
Any ideas?
Change your query to
select * from users where name like '?'
If you want to do a wildcard match, put the wildcards as part of the string that you're binding to the variable. If you don't want to do a wildcard match, then don't.
Note that like and = have the same performance except when your wildcard character is first in the string (for example, '%bob') as in that case the query optimizer can't use indexes as well to find the row(s) that you're looking for.
you can't search an exact match if the sql contains % symbols, as they are wildcards. you'll need to change the sql to
select * from users where name = '?'
for an exact match
(you can also use select * from users where name like '?' but that's more inefficient)
What is keeping you from changing the SQL?
The Like condition is for 'similar' matches, while the '=' is for exact matches.
Related
I came across the same issue as the author of this question (PreparedStatement IN clause alternatives?), and wondered if using mysql's REGEXP would be an elegant way of getting the same functionality of IN while using only one PreparedStatement for varying number of values to match? Some example SQL here to show what I am talking about:
SELECT first_name, last_name
FROM people
WHERE first_name REGEXP ?
Multiple values could be supplied using a string like "Robert|Janice|Michael". I did not see REGEXP mentioned anywhere in that post.
Technically, yes, it is an alternative.
Note, however, that using a regex for matching is less efficient that the in operator ; it incurs more work for the database, that needs to initialize the regex engine, and run it against each and every value (it cannot take advantage of an index).You might not notice it on small volumes, but as your data grows larger this might become an issue. So I would not recommend that as a general solution: instead, just write a few more code lines in your application to properly use the in operator, and use regexes only where they are truly needed.
Aside: if you want to match the entire string, as in does, you need to surround the list of values with ^ and $, so the equivalent for:
first_name in ('Robert', 'Janice', 'Michael')
Would be:
first name regexp '^(Robert|Janice|Michael)$'
Another approach:
FIND_IN_SET(name, 'Robert,Janice,Michael')
Yes, that could be substituted in. But it must be a commalist of the desired values. This also works for FIND_IN_SET(foo, '1,123,45'). Note that 12 will not match.
I need to do the following query in sqlite:
select * from table where field = "somekindofdata"
however, I need to first remove all the special characters from field before I do the comparison. In java, it would look something like this:
field = field.replaceAll("[\\s+\\W+]","");
is this possible ?
I need to implement stringUtils Class indexOf() method in postgresql.
Lets say I have a table in which url is one of the column.
url : "http://paypal-info.com/home.webapps.cgi-bin-limit/webscr.cmd-login-submit"
My requirement is to find the index of the 3rd occurence of '/' in the above url and do substring and take only paypal-info.com host name in Postgresql Query
Any idea on implementing this would be grateful.
Thanks
Have you tried split_part method?
SELECT split_part('http://paypal-info.com/home.webapps.cgi-bin-limit/webscr.cmd-login-submit', '/', 3)
Result:
split_part
paypal-info.com
For other string functions try this doc:
http://www.postgresql.org/docs/9.1/static/functions-string.html
Edit: as for indexOf itself I don't know any built-in postgres solution. But using two string functions You can achieve it like this:
SELECT strpos('http://paypal-info.com/home.webapps.cgi-bin-limit/webscr.cmd-login-submit', split_part('http://paypal-info.com/home.webapps.cgi-bin-limit/webscr.cmd-login-submit', '/', 4)) - 1 as index_of;
The string functions and operators section of the manual is the equivalent of String.indexOf, e.g.
select position('/' in 'http://paypal-info.com/home.webapps.cgi-bin-limit/webscr.cmd-login-submit');
however it doesn't offer the option to get the n'th occurrence.
You're really approaching this all wrong. You should use proper URL parsing code to extract the host portion, not attempt to roll your own or use regex / splitting / string mangling.
PostgreSQL doesn't have a native URL/URI type, but its procedural languages do and it's trivial to wrap suitable functions. e.g. with PL/Python:
create language plpythonu;
create or replace function urlhost(url text) returns text
language plpythonu
immutable strict
as $$
import urlparse
return urlparse.urlparse(url).netloc
$$;
then:
regress=# select urlhost('http://paypal-info.com/home.webapps.cgi-bin-limit/webscr.cmd-login-submit');
urlhost
-----------------
paypal-info.com
(1 row)
If you'd prefer to use PL/Perl, PL/V8, or whatever, that's fine.
For best performance, you could write a simple C function and expose that as an extension.
Just replace 3 with N to get the index of the Nth '/' in a given string
SELECT length(substring('http://asd/asd', '(([^/]*/){3})')) - 1
To extract the host name from url you can use
SELECT substring('http://asd.com:234/qwe', 'http://([^:]+).*/')
Tested here: SQLFiddle
I have a table of project in which i have a project name and that project name may contain any special character or any alpha numeric value or any combination of number word or special characters.
Now i need to apply keyword search in that and that may contain any special character in search.
So my question is: How we can search either single or multiple special characters in database?
I am using mysql 5.0 with java hibernate api.
This should be possible with some simple sanitization of you query.
e.g: a search for \#(%*#$\ becomes:
SELECT * FROM foo WHERE name LIKE "%\\#(\%*#$\\%";
when evaluated the back slashes escape so that the search ends up being anything that contains "\#(%*#$\"
In general anything that's a special character in a string can be escaped via a backslash. This only really becomes tricky if you have a name such as: "\\foo\\bar\\" which to escape properly would become "\\\\foo\\\\bar\\\\"
A side note, please proof read your posts prior to finalizing. Its really depressing and shows a lack of effort when your questions title has spelling errors in it.
SQLite statement 'abc' LIKE 'ABCd' will return true. So my question is how to make an SQLite query that will return only exact record matches for a particular query.
The LIKE operator has two modes that can be set by a pragma. The default mode is for LIKE comparisons to be insensitive to differences of case for latin1 characters. Thus, by default, the following expression is true:
'a' LIKE 'A'
But if the case_sensitive_like pragma is enabled as follows:
PRAGMA case_sensitive_like=ON;
Then the LIKE operator pays attention to case and the example above would evaluate to false.
for exact record match you need to use = sign.
ex : abc = abc.
and if you want all records which contain abc words. You need to write
abc like '%abc%' in your sqllite query.