MySQL question about getting concret columns [duplicate] - mysql

This question already has an answer here:
MySQL LIKE query with underscore
(1 answer)
Closed 4 years ago.
I have a table in my database that contains information like this:
activity: R1A1, R1A2, R1A2_2
My problem is where I'm trying to get all the activities that do not contain the second part (_2).
I'm trying this query: SELECT activity FROM table_name WHERE activity NOT LIKE '%_2' but I'm getting only the activity R1A1. This is because R1A2 contains a number two on its name. How can I solve it? What is the correct query to do that? I want to get all the activities without _2 or something like that on its name.
If I do in an inverse method (SELECT activity FROM table_name WHERE activity NOT LIKE 'R1%' I get the correct results.
How can I get what I need? Thanks for your answers!

in MYSQL, the underscore is a wildcard, much like the % except it matches one character. You can escape it with \ to get the literal.
Here is the correct query:
SELECT activity FROM table_name WHERE activity NOT LIKE '%\_2'

The underscore in LIKE is a wildcard that matches any character. You can escape it. Here is one method:
SELECT activity
FROM table_name
WHERE activity NOT LIKE '%$_2' ESCAPE '$';

Related

Using a MySQL Select with a RegEx Expression embedded within a String

I am using PHP to access a mysql database field that contains up to 2500 characters per record.
I want to build queries that will return only the records that include a single word, like 'taco'.
Sometimes, however, the user will need to search for a word like 'jalapeno'. Except that jalapeno may exist in the database as 'jalapeno' or as 'jalapeño'. The query should return both instances.
As a further complication, the user may also need to search for a word like 'creme', which may appear as 'creme' or 'créme', but never as 'crémé'.
It seems like I should be able to construct something that uses a replace, and then a Regular Expression, so that the letter 'n' is always replaced with '[n|ñ]', and then search for a string with an embedded Regular Expression like this: 'jalape[n|ñ]o'. Except that does not work. MySQL treats the RegEx syntax as literals.
None of the following return the results that I am looking for:
SELECT id, record FROM table WHERE record like '%jalapeno%';
SELECT id, record FROM table WHERE record REGEXP 'jalapeno';
SELECT id, record FROM table WHERE record REGEXP 'jalape[n|ñ]o';
SELECT id, record FROM table WHERE REGEXP_LIKE(record, 'jalape[n|ñ]o', 'im');
Additionally, I can use PHP to do a replacement of the potential characters, but I end up with stuff like this:
SELECT id, record FROM table WHERE (record like '%creme%' || record like '%crémé%');
I would be Ok with a search like this, but it seems overly complicated to construct programmatically:
SELECT id, record FROM table WHERE (record like '%creme%' || record like '%crémé%' || record like '%cremé%' || record like '%cremé%' );
Is there a MySQL method that provides a REGEX 'OR' to be embedded within a String?
Maybe something like this:
SELECT id, record FROM table WHERE record like '%cr[e|é]m[e|é]%' ;
Or is there another solution that would not require the construction of an excessively convoluted SQL Statement?
Thanks for anyone who spent time trying to figure this out.
As I commented above, REGEXP_LIKE() does not appear to be a valid MySQL function for the current release.
Here is my solution; Note that this works for MySQL 5.7.x.
SELECT id, record FROM table WHERE record RLIKE 'jalape(n|ñ)o';

Mysql regexp to get right table names from database schema [duplicate]

This question already has an answer here:
How to match a fixed string ending with a number using regex [duplicate]
(1 answer)
Closed 2 years ago.
I'm trying to select, from mysql, some specific tables that matches a pattern.
The specific pattern I'm looking for is like 'my_table_number'. For example, my_table_436814 or my_table_35413. The thing is that there are other tables that looks like my_table_old_14353 or my_table_351434_times. I just want to filter out the ones that are my_table_number.
I have tried different patterns, but failed to get what I really need.
The most closest approach was with this:
select table_name from
information_schema.columns ca
where ca.table_name REGEXP '[0-9]$'
How can I achieve what I'm looking for?
Use
REGEXP '^my_table_[0-9]+$'
See proof
NODE
EXPLANATION
^
the beginning of the string
my_table_
'my_table_'
[0-9]+
any character of: '0' to '9' (1 or more times (matching the most amount possible))
$
before an optional \n, and the end of the string

MySQL throws an error when receiving my query [duplicate]

This question already has an answer here:
How to escape value keyword in mysql while using Select statement
(1 answer)
Closed 3 years ago.
I have to access a MySQL database that looks like this:
LOG_ID KEY TARGET CREATOR
1 okaytest 297d09d5-55fe faec09c0-159e
I can do the following query:
SELECT * FROM DATABASE WHERE LOG_ID=1
This would return me the column correctly.
But I can't do the following query.
SELECT * FROM DATABASE WHERE KEY='okaytest'
I believe that there might be a problem with the word KEY being a reserved keyword in MySQL, but I have to access that specific database, I can't change it's name and I must select it from the key
try like below by using the backtick `
SELECT * FROM DATABASE WHERE `KEY`='okaytest'
actually for reserve word you have to use this backtick otherwise it will thorow error here is the reserve word list
another options better not to use reserve word or incase of necessary you have use it by using backtick

MYSQL Find entries that contain more than 7 numbers

I need to find entries that contain more than 7 numbers in one of my mysql tables BUT the numbers are separated by letters or anything else.
What I have is this little piece of code I use to find entries like dsc123456789:
select * from crawl where title regexp '[0-9]{7}'
How can I find entries like dsc-123-456_78B9? I tried different things but without success so far.
Thanks
You can use the following solution:
SELECT *
FROM crawl
WHERE title REGEXP '(([^[:digit:]])?[[:digit:]]){8,}';
Why the original query of the answer doesn't work?
-- this query doesn't work!
SELECT *
FROM crawl
WHERE title REGEXP '\d([^\d]?\d){7,}'
MySQL can't use character groups like \d (digits). So the query fails every time. On PHP and other languages the regular expression would look like this:
\d([^\d]?\d){7,}
but on MySQL this isn't valid. So you have to use the character classes of MySQL to solve this:
(([^[:digit:]])?[[:digit:]]){8,}
Hint: Make sure you use {8} or {8,} instead of {7} since you want to find all entries with more than 7 numbers / digits.

Retrving data from MySql with case sensitivity [duplicate]

This question already has answers here:
How can I make SQL case sensitive string comparison on MySQL?
(12 answers)
Closed 8 years ago.
I have a Login table in MySql database . . In table there is a column by cname and one of the value is 'Raghu'. My question is when i write the query as
Select *from Login where cname='raghu';
Then it is retrieving the record which contains 'Raghu' . I want it to retrieve according to case . How can I retrieve with case sensitively, values in the data of tables.
Use: 10.1.7.7. The BINARY Operator
The BINARY operator casts the string following it to a binary string. This is an easy way to force a comparison to be done byte by byte rather than character by character.
Select * from Login where binary cname='raghu';
SELECT * from Login WHERE STRCMP(cname,'Raghu')=0;
Can you try this, you can use LOWER FUNCTION in either column name LOWER('cname') or in value LOWER('raghu');
Select *from Login where LOWER(`cname`) = 'raghu';