SELECT *
FROM list
WHERE list_item LIKE "%_1375_%"
returns results it should not. For example a result with 13753 in the list_item instead of 1375, even though the 3 comes before the underscore.
_13753_ and _1375_ are written above and not suppose to be italic.
Is there anyway to fix that?
From MySQL reference manual here
SQL pattern matching enables you to use “_” to match any single
character and “%” to match an arbitrary number of characters
(including zero characters).
So, you'll have to escape them to match a literal underscore character. Like so:
SELECT * FROM list
WHERE list_item LIKE "%\_1375\_%"
Underscore means any character. Are you looking for values with an underscore? In that case you need to escape it
SELECT *
FROM list
WHERE list_item LIKE "%\_1375\_%"
Try this one
LIKE '%[_]1375[_]%'
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!
Quick questions, I bet the answer is so simple and I am just being blind.
I want to select from the database all the names that only start with "test_1_1_".
I would guess that I do this with;
SELECT * FROM my_table WHERE names LIKE "test_1_1_%";
This doesn't seem to work.
The results keep showing up as
test_1_1_1
test_1_1_2
test_1_11_1
test_1_11_2
test_1_12_1
test_1_12_2
How can I select with MySQL only the results that start with "test_1_1_"?
Thank you in advance.
Wesley
Underscore has a special meaning in LIKE and needs to be escaped:
SELECT * FROM my_table WHERE names LIKE 'test\_1\_1\_%';
You could also use REGEXP here, and avoid the escaping problem:
SELECT * FROM my_table WHERE names REGEXP '^test_1_1_';
When you use _ inside LIKE, it will mean replace that space with any character.
For example, searching for something like field LIKE 'a_' will result in any field with 2 characters starting with "a".
If you really want to search for the underscore characters, you need to escape the value with \ and your query will look like this: LIKE 'test\_1\_1\_%';
The underscore is a single character wildcard when use with LIKE. So to specifically locate an underscore it needs to be "escaped" as follows:
select
*
from mytable
where names like 'test\_1\_1\_%' escape '\'
To test for literal instances of a wildcard character, precede it by
the escape character. If you do not specify the ESCAPE character, \ is
assumed.
https://dev.mysql.com/doc/refman/8.0/en/string-comparison-functions.html
Can do this:
SELECT * FROM my_table WHERE names LIKE "test\_1\_\1\_%";
For example, Search is a commonly used functions.
I will generate a query string like "SELECT * FROM table WHERE col LIKE '%{keyword}%'"
but the keyword's value is '%', it does not work, how to fix it.
In addition, what other characters need to be aware of?
Just use a backslash to escape the percent. For example, if your keyword were 5% discount, then you would use:
SELECT * FROM table WHERE col LIKE '%5\% discount%'
The documentation lists only two characters which have a special meaning in LIKE:
% - matches any number of characters
_ - matches any single character
If you want to use either of these characters literally in a LIKE expression, then you will need to escape them.
Consider the following regex
#(.*\..*){2,}
Expected behaviour:
a#b doesnt match
a#b.c doesnt match
a#b.c.d matches
a#b.c.d.e matches
and so on
Testing in regexpal it works as expected.
Using it it in a mysql select doesn't work as expected. Query:
SELECT * FROM `users` where mail regexp '#(.*\..*){2,}'
is returning lines like
foo#example.com
that should not match the given regex. Why?
I think the answer to your question is here.
Because MySQL uses the C escape syntax in strings (for example, “\n”
to represent the newline character), you must double any “\” that you
use in your REGEXP strings.
MYSQL Reference
Because your middle dot wasn't properly escaped it was treated as just another wildcard and in the end your expression was effectively collapsed to #.{2,} or #..+
#anubhava's answer is probably a better substitute for what you tried to do though I would note #dasblinkenlight's comment about using the character class [.] which will make it easy to drop in a regex you've already tested in at RegexPal.
You can use:
SELECT * FROM `users` where mail REGEXP '([^.]*\\.){2}'
to enforce at least 2 dots in mail column.
I would match two dots in MySQL using like:
where col like '%#.%.%'
The problem with your code is that .* (match-everything dot) matches dot '.' character. Replacing it with [^.]* fixes the problem:
SELECT *
FROM `users`
where mail regexp '#([^.]*[.]){2,}'
Note the use of [.] in place of the equivalent \.. This syntax makes it easier to embed the regex into programming languages that use backslash as escape character in their string literals.
Demo.
I want to match the string having escape characters with particular column in a table.
SELECT * FROM table WHERE col LIKE 'MESSRESTAURANGER AB\\MESSVEGEN 1\\STOCKH';
Though there is matching data in table, query result is empty set. But the same query works fine in oracle. What is the issue with mysql?
You miss %:
SELECT * FROM table WHERE col LIKE '%MESSRESTAURANGER AB\\MESSVEGEN 1\\STOCKH%';
But it should work without escaping:
SELECT * FROM table WHERE col LIKE '%MESSRESTAURANGER AB\MESSVEGEN 1\STOCKH%';
Fiddle http://sqlfiddle.com/#!9/a7ba59/2
EDIT:
SELECT * FROM t WHERE n LIKE '%MESSRESTAURANGER AB\\\\\\\\MESSVEGEN 1\\\\\\\\STOCKH%'
Because MySQL uses C escape syntax in strings (for example, “\n” to
represent a newline character), you must double any “\” that you use
in LIKE strings. For example, to search for “\n”, specify it as “\n”.
To search for “\”, specify it as \\\\; this is because the
backslashes are stripped once by the parser and again when the pattern
match is made, leaving a single backslash to be matched against.
Fiddle http://sqlfiddle.com/#!9/ac46b/9