I want to remove the names which may be registered with fake names.
As the developer forgot to put validation on form registration.
Now i want to remove the fake names.
And for checking if that name is fake or not, I am checking if the name content any numbers or not ?
This is my query which i have written but its not working...
SELECT registration.regi_id, student.first_name,
student.cont_no, student.email_id,
registration.college,
registration.event_name,
registration.accomodation
FROM student, registration
WHERE student.stud_id = registration.stud_id
AND student.first_name NOT RLIKE '%[0-9]%'
How to fix this problem ?
Sorry for my language issues,
P.S.
There are many names in "first_name" field like "asdfasdf12323", i don't want that kind of names to be shown on list.
Your column may contain Alphanumeric characters also.YOu need to filter Numbers and Alphanumeric characters both
For Alphanumeric characters Try REGEXP '^[A-Za-z0-9]+$'
For numbers Try REGEXP '[0-9]'
Well as far as the regex is involved, your expression is only looking for a single number. Also, your 'NOT RLIKE' isn't using regex but is doing a basic string search for the literal '[0-9]' I believe. MySql has support for regex, and your last clause would look like so: AND student.first_name NOT REGEXP '[0-9]*'
Related
I have a small mysql database with a column which has format of a field as following:
x_1_1,
x_1_2,
x_1_2,
x_2_1,
x_2_12,
x_3_1,
x_3_2,
x_3_11,
I want to extra the data where it matches last '_1'. So if I run a query on above sample dataset, it would return
x_1_1,
x_2_1,
x_3_1,
This should not return x_2_12 or x_3_11.
I tried like '%_1' but it returns x_2_12 and x_3_11 as well.
Thank you!
A simple method is the right() function:
select t.*
from t
where right(field, 2) = '_1';
You can use like but you need to escape the _:
where field like '%$_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!
So I'm trying to find what "special characters" have been used in my customer names. I'm going through updating this query to find them all one-by-one, but it's still showing all customers with a - despite me trying to exlude that in the query.
Here's the query I'm using:
SELECT * FROM customer WHERE name REGEXP "[^\da-zA-Z\ \.\&\-\(\)\,]+";
This customer (and many others with a dash) are still showing in the query results:
Test-able Software Ltd
What am I missing? Based on that regexp, shouldn't that one be excluded from the query results?
Testing it on https://regex101.com/r/AMOwaj/1 shows there is no match.
Edit - So I want to FIND any which have characters other than the ones in the regex character set. Not exclude any which do have these characters.
Your code checks if the string contains any character that does not belong to the character class, while you want to ensure that none does belong to it.
You can use ^ and $ to check the while string at once:
SELECT * FROM customer WHERE name REGEXP '^[^\da-zA-Z .&\-(),]+$';
This would probably be simpler expressed with NOT, and without negating the character class:
SELECT * FROM customer WHERE name NOT REGEXP '[\da-zA-Z .&\-(),]';
Note that you don't need to escape all the characters within the character class, except probably for -.
Use [0-9] or [[:digit:]] to match digits irrespective of MySQL version.
Use the hyphen where it can't make part of a range construction.
Fix the expression as
SELECT * FROM customer WHERE name REGEXP "[^0-9a-zA-Z .&(),-]+";
If the entire text should match this pattern, enclose with ^ / $:
SELECT * FROM customer WHERE name REGEXP "^[^0-9a-zA-Z .&(),-]+$";
- implies a range except if it is first. (Well, after the "not" (^).)
So use
"[^-0-9a-zA-Z .&(),]"
I removed the + at the end because you don't really care how many; this way it will stop after finding one.
This is question pertaining to SQL Server 2014. I have a table xxx. There is a column col1 of type varchar. The values in this column can have alphanumeric characters like 1A324G. There can also be special characters along with alphanumeric like !2A93C or #AC934D, etc.
There can be any special character (eg: !$#^().-_) in a value for this column. I wanted to extract data with only alphanumeric values and NOT any special characters in it. I was trying to use the LIKE clause with wildcard search pattern but I am not able to weed out the ones with only alphanumeric values.
Can someone please help me and let me know how I can do it?
It's been a while since I've played with sql but something like this should work.
SELECT *
FROM xxx
WHERE col1 NOT LIKE '%!%' OR '%$%';
I can't find a proper way to escape apostrophe sign(’) in my mysql query. Regexp I have, works fine with online tools for regexp testing.
Problematic example is the string G’Schlössl.
I want to have optional apostrophe sign in the query in front of the s character G(’?)Schlö(’?)ssl for all the different cases which could occur in other strings. I am not sure if the problem is caused by incorrect sign escaping but I have tried many options like ’?, \’?, \’{0,1} which works for the first occurrence but doesn't for the second optional one and cause query to return nothing. Other possibilities like ’’?, [’]?, [\’]?, [\’]{0,1} does not work even for the first one.
select id, name from restaurant where name regexp '.*g\’?(s|ß|ss|sz)chl(o|ö|oe)\’?s.*';
When I remove the last \’? it works:
select id, name from restaurant where name regexp '.*g\’?(s|ß|ss|sz)chl(o|ö|oe)s.*';
When I replace the last \’? with x? it works as well:
select id, name from restaurant where name regexp '.*g\’?(s|ß|ss|sz)chl(o|ö|oe)x?s.*';
Any ideas where the problem is or what else to try?
This thread explains escaping normal single quote only, which seems not to work in my case.
Instead of \’?, try (’)?. I'm thinking that the ? may apply to only the last byte of ’. By using parentheses instead, the ? applies to the entire 3 bytes (hex E28099) of the "RIGHT SINGLE QUOTATION MARK".
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}"