I want to filter out those with field not like '%_[0-9]+' ,
but it turns out that MySQL doesn't take it as regex,
is that possible in MySQL?
That happens because of LIKE is not supposed to accept regular expression as a parameter. There is REGEXP for such things
WHERE field NOT REGEXP '%_[0-9]+'
Related
I have a small mysql database with a column which has format of a field as following:
x_1_1,
x_1_2,
x_1_2,
x_2_1,
x_2_12,
x_3_1,
x_3_2,
x_3_11,
I want to extra the data where it matches last '_1'. So if I run a query on above sample dataset, it would return
x_1_1,
x_2_1,
x_3_1,
This should not return x_2_12 or x_3_11.
I tried like '%_1' but it returns x_2_12 and x_3_11 as well.
Thank you!
A simple method is the right() function:
select t.*
from t
where right(field, 2) = '_1';
You can use like but you need to escape the _:
where field like '%$_1' escape '$'
Or use regular expressions:
where field regexp '_1$'
The underscore character has special significance in a LIKE clause. It acts as a wildcard and represent one single character. So you would have to escape it with a backslash:
LIKE '%\_1'
RIGHT does the job too, but it requires that you provide the proper length for the string being sought and is thus less flexible.
Duh, I found the answer.
Use RIGHT (col_name, 2) = '_1'
Thank you!
I have a table with tens of thousands of VIN numbers. Many of them look along the lines of this:
6MMTL#A423T######
WVWZZZ3BZ1?######
MPATFS27H??######
SCA2D680?7UH#####
SAJAC871?68H06###
The # represents a digit and the ? a letter (A-Z).
I want to search for the following: 6MMTL8A423T000000.
I am struggling to work out the logic. Should I use a function? Should I use mysql regex?
A regular expression match would be a good way to approach this problem. What you need to do is convert the vin expressions into valid regular expressions that represent the logic you've indicated. Here's a simple way to do that:
replace(replace(vin,'#','[0-9]'),'?','[A-Z]')
This would convert 6MMTL#A423T###### into 6MMTL[0-9]A423T[0-9][0-9][0-9][0-9][0-9][0-9]. Now using this converted format, do a regular expression match query:
select vin
from vins
where '6MMTL8A423T000000' regexp replace(replace(vin,'#','[0-9]'),'?','[A-Z]')
Sample Output: 6MMTL#A423T######
Demo: http://www.sqlfiddle.com/#!2/ee4de/4
I need a MySQL pattern to match a number, followed by a question mark.
I need something like
... like '%[0-9]?%'
but I have no idea how to create this regular expression.
http://dev.mysql.com/doc/refman/5.0/en/pattern-matching.html does not help.
Thanks!
you could try this:
SELECT * FROM YourTable WHERE YourField REGEXP '[0-9]\\?'
That will return rows where YourField contains a number followed by a ? anywhere in the value.
If you want it to only match if the whole field is a number followed by a ?. I.e. 9? then you could use this regex instead:
^[0-9]\\?$
I guess you're looking for something like this:
select * from table
where field rlike '[0-9]\\?'
Remember to escape the question mark. Otherwise, it will make the number optional.
Source.
I have tried several regex patterns (designed for use with PHP because I couldn't find any for MySQL) for URL validation, but none of them are working. Probably MySQL has a slightly different syntax.
I've also tried to come up with one, but no success.
So does anyone know a fairly good regex to use with MySQL for URL validation?
According to article 11.5.2. Regular Expressions in MySQL's documentation, you can perform selections with a regular expression with the following syntax
SELECT field FROM table WHERE field REGEX pattern
In order to match simple URLS, you may use
SELECT field FROM table
WHERE field REGEXP "^(https?://|www\\.)[\.A-Za-z0-9\-]+\\.[a-zA-Z]{2,4}"
This will match most urls like
www.google.il
http://google.com/
http://ww.google.net/
www.google.com/index.php?test=data
https://yahoo.dk/as
http://goo.gle.com/
http://wt.a.x24-s.org/ye/
www.website.info
But not
htp://google.com
ww.google.com/
www-google.com
http://google.c
http://goo#.com
httpf://google.com
Although the answer KBA posted works, there are some inconstancies with the escaping.
The proper syntax should be, this syntax works in MySQL as well as in PHP for example.
SELECT field FROM table
WHERE field REGEXP "^(https?:\/\/|www\.)[\.A-Za-z0-9\-]+\.[a-zA-Z]{2,4}"
The above code will only match if the content of 'field' starts with a URL. If you would like to match all rows where the field contains a url (so for example surrounded by other text / content) just simply use:
SELECT field FROM table
WHERE field REGEXP "(https?:\/\/|www\.)[\.A-Za-z0-9\-]+\.[a-zA-Z]{2,4}"
Is it possible to get the (first?) match of a regex and output it within a select? It looks like the REGEXP function only return whether there has been a match or not. I want to be able to extract information out of a varchar column without having to use complex SUBSTRING-LOCATION nestings.
Any ideas?
http://dev.mysql.com/doc/refman/5.1/en/regexp.html that's all there is. You can't do more than pattern comparison.