I have this query:
"SELECT * FROM i开发者_StackOverflow中文版nformations WHERE ". $id ." IN (ids)"
It only works if $id is the first value from ids... in ids values are "1,2,3,4,5".
Is there a way for it to work with the rest of the ids?
Would this work for you?
"SELECT *
FROM Informations
WHERE ids LIKE \"" . $id . ", %\" -- try to match against the first value in ids
OR ids LIKE \"%," . $id . ",%\" -- try to match against a value in ids that is neither the first nor the last value
OR ids LIKE \"%," .$id . "\" -- try to match against the last value found in ids"
If ids
is a field containing comma-delimited values, then your query is like:
SELECT * FROM `informations` WHERE 3 IN ("1,2,3,4,5")
Instead of what it should be:
SELECT * FROM `informations` WHERE 3 IN (1,2,3,4,5)
There is no automatic tokenisation (splitting on ,
) performed; the one value of ids
is not automatically converted into a list for you such that IN
can work.
Unfortunately your table design has been your undoing here. Can you split the IDs into a separate table using the principle of database normalisation?
Then your query might look like:
SELECT * FROM `informations` WHERE 3 IN (
SELECT `id`
FROM `ids`
WHERE `informations`.`id` = `ids`.`information_id`
)
BTW, "information" is a non-countable noun and, as such, "informations" is wrong.
Update (thanks for the idea, a1ex07!)
Although this is hackery and I still suggest fixing your table layout, I'll be kind and suggest a quick fix.
Willempie was close with:
$query = 'SELECT *
FROM `informations`
WHERE `ids` LIKE "%' . $id . '%"';
Unfortunately, a wildcard match isn't quite powerful enough. Consider if ids
is like "1,6,9,12,35,4"
and $id
is like 3
. You get a false positive. The LIKE
statement needs to be aware of the commas.
You can add multiple cases:
$query = 'SELECT *
FROM `informations`
WHERE `ids` LIKE "%,' . $id . ',%"
OR `ids` LIKE "%,' . $id . '"
OR `ids` LIKE "' . $id . ',%"';
Or, for brevity, you can work around this with regular expressions:
$query = 'SELECT *
FROM `informations`
WHERE `ids` REGEXP "(^|,)' . $id . '(,|$)"';
For any $id
you wish to find, before it must be the start of ids
(^
) or a comma; after it must be a comma or the end of ids
($
). This ensures that $id
must be found as a whole, comma-delimited token.
It's a little like "Whole Word Only" in word processor searches, but with commas separating "words" instead of spaces.
Update 2
Another way uses FIND_IN_SET
, which performs a search within a comma-delimited string:
$query = 'SELECT *
FROM `informations`
WHERE FIND_IN_SET("' . $id . '", `ids`)';
Your query is technically correct but the values for 'ids' are not.
You should enclose the values of ids within single quotes. If I were to write the code without using ids, it would be like this:
"SELECT * FROM informations WHERE ". $id ." IN ('1','2','3','4','5')"
More info on this rule here: http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html#function_in
I'm not sure what you are trying to achieve. If ids
is a column in informations
your code is just a weird way to express "SELECT * FROM informations WHERE ids = ". $id "
; If it is a string, I don't see why you need WHERE
at all : expression $id in (1,2,3,4,5)
is constant, it doesn't require interaction with database; in any case you either grab all rows from informations
or none.
UPDATE
Another suggestion :maybe ids
is a string field in informations
that contains "1,2,3,4,5". In this case you cannot get expected results by using WHERE ... IN
. You need to use REGEXP to check if string contains your number.
It has to be column name then IN (comma separated values here).
SELECT column_name(s)
FROM table_name
WHERE column_name IN (value1,value2,...)
You did an error in sql syntax.
This is the correct syntax
"SELECT * FROM informations WHERE ids IN (". $id .")";
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