Comparing Comma separated String in Mysql - mysql

I need to compare a string with comma separated values in a stored procedure.
input RANDOM string is = "'aa','ab','ac'"
I need something like
I need a resultant effect similar to the one below without using DYNAMIC SQL.
SELECT * FROM table1
WHERE table1.field1 LIKE %aa% OR
table1.field1 LIKE %ab% OR
table1.field1 LIKE %ac%
I cannot use find_in_set as the input string is variable and not fixed

You can approach in this way:
SELECT
*
FROM table1
WHERE
table1.field1 REGEXP
REPLACE (REPLACE ("'aa','ab','ac'",'\'',''),',','|');
In general:
SELECT
*
FROM table1
WHERE
table1.field1 REGEXP
REPLACE (REPLACE (PUT_YOUR_INPUT_STRING_HERE,'\'',''),',','|')
In order to understand what's going on there the following query might lead towards that:
SELECT
REPLACE("'aa','ab','ac'",'\'','') afterFirstReplace,
REPLACE(REPLACE("'aa','ab','ac'",'\'',''),',','|') afterSecondReplace;
afterFirstReplace afterSecondReplace
aa,ab,ac aa|ab|ac

Related

Oracle SQL - Regex to search columns with only 1 letter

I want to to create a regex to find all columns that only have a single character ([A-Z]) as name, like N or M but not NM.
I've tried:
SELECT * FROM 'table' WHERE Name REGEXP '^[A-Z]'
But it's not displaying the expected result.
Try ^[A-Z]$.
You then state that this character is first and also last character of the value.
The regex functions in Oracle work only on one column. So, to search for just one character in a column, you would do the following:
select * from yourTable where REGEXP_LIKE (col1, '^[A-z]$');
Now, to search all the char/varchar columns on your table, you'll need to chain the regex expressions together, like so:
select * from yourTable where REGEXP_LIKE (col1, '^[A-z]$') or REGEXP_LIKE (col3, '^[A-z]$');
SQL solution:
where name in ('N','M')

like clause doesn't work as it said in MySQL SQL

I have a table, such as
create table table1(
name varchar(32),
);
And there's some data in it. When I select like this:
select * from table1 where name like 'Jack2%';
there will be Jack2.
But if I select like this:
select * from table1 where name like 'Jack[0-9]%';
there will be nothing;
And I also tried regexp to subsitute like, but it also didn't work!
What's wrong?
You've confused two different pattern-matching mechanisms. SQL LIKE uses % to match anything and _ to match any single character; it does not have anything like [0-9] to match a digit. That looks like a character class from a regular expression.
Standard SQL has no support for regular expressions at all, but MySQL does - you just have to use RLIKE (or REGEXP, but that doesn't read as nicely IMO) instead of LIKE. But that means that you have to replace the % with the regular-expression equivalent .*, too.
SELECT * FROM table1 WHERE name RLIKE 'Jack[0-9].*';
Fiddle
MySQL REGEX
select * from Table1 where `name` REGEXP 'Jack[0-9]'
You can use RLIKE instead
SELECT * FROM table1 WHERE name RLIKE 'Jack[0-9].*';
And please note the the '%' operator won't work with RLIKE, you have to use a regular expression pattern like '.*' instead.

MySql find a value in a comma separated set

I have values stored like this in a field 1,255,230,265.
Is there a function in MySQL that will give me the second value in that string? In this case it'll be 255.
I tried using locate, but that does not seem to be meant for this.
Try this
select SUBSTRING_INDEX(SUBSTRING_INDEX(field_name,',',2),",",-1) from table_name
You might want to use SUBSTRING_INDEX() function.
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(field,',',2),',',-1)
FROM yourTable.
This grabs everything infront of the second comma, then grabs everything after the last comma (-1)
Try This
select * from Table1 where ',' + Nos+ ',' like '%,255,%'
Refer:
MySQL query finding values in a comma separated string
mysql check if numbers are in a comma separated list
Use FIND_IN_SET() function:
SELECT *
FROM tableA
WHERE FIND_IN_SET(255, columnName)
OR
Use LIKE operator
SELECT *
FROM tableA
WHERE CONCAT(',', columnName, ',') LIKE '%,255,%'

Mysql like to match pattern at end of string

I have the following strings in the following pattern in a table in my db:
this_is_my_string_tester1
this_is_my_string_mystring2
this_is_my_string_greatstring
I am trying to match all strings that start with a specific pattern split by underscores i.e.this_is_my_string_ and then a wildcard final section
Unfortunately there is an added complication where some strings like the following:
this_is_my_string_tester1_yet_more_text
this_is_my_string_mystring2_more_text
this_is_my_string_greatstring_more
Therefore taking the following as examples:
this_is_my_string_tester1
this_is_my_string_mystring2
this_is_my_string_greatstring
this_is_my_string_tester1_yet_more_text
this_is_my_string_mystring2_more_text
this_is_my_string_greatstring_more
I am trying to have returned:
this_is_my_string_tester1
this_is_my_string_mystring2
this_is_my_string_greatstring
I have no idea how to do this with a like statement. Is this possible if so how?
EDIT
There is one final complication:
this_is_my_string
needs to be supplied as a list i.e in
(this_is_my_string, this_is_my_amazing_string, this_is_another_amazing_string)
SELECT * FROM atable WHERE afield REGEXP 'this_is_my_string_[a-z]+'
It might be faster if you have an index on afield and do
SELECT * FROM atable WHERE afield REGEXP 'this_is_my_string_[a-z]+'
AND afield LIKE 'this_is_my_string_%'
After edit of question:
Either
SELECT * FROM atable
WHERE afield REGEXP '(this_is_my_string|this_is_my_amazing_string)_[a-z]+'
or maybe you want something like having a table with the prefixes:
SELECT *
FROM atable AS t,
prefixes AS p
WHERE afield REGEXP CONCAT(p.prefix, '_[a-z]+')
As by the reference documentation this should not be possible, as a pattern (string literal) is required. Give it a try nevertheless.
There the answer of #KayNelson with LIKE (?) and INSTR might do instead of REGEXP.
try this
SELECT * FROM db.table WHERE strings LIKE 'this_is_my_string_%' AND instr(Replace(strings,"this_is_my_string_",""),"_") = 0;
It checks if more _ occurs after replacing the standard "this_is_my_string_"

Use '%' with column names in MYSQL select statement?

I have a query that looks at partial matches within two mysql tables to make a join:
SELECT table1.column, table2.column FROM table1, table2 WHERE table1.val LIKE table2.val
This works fine as a join, but... some of the values in table2 are actually substrings of the values in table one—specifically they're urls. So, table1.val might equal http://google.com while table2.val = google.com.
How do I use the '%' operator around the table2 val to make this comparison.
Thanks in advance!
Like this:
... WHERE table1.val LIKE CONCAT('%', table2.val, '%')
Note that this will not perform as well as table1.val = table2.val, as it must now search all rows in table2.
Q: How do I use the '%' operator around the table2 val to make this
comparison.
A: You don't :)
You can specify a column by name (e.g. "mycolumn"), by fully qualified name (e.g. "mytable.myname") or by ordinal (e.g. "1").