I have query like this:
SELECT * FROM activity
WHERE (((userId = 1 OR userId IN(SELECT userId FROM follower WHERE followerId = 1))
AND activityType IN(1, 2, 3))
OR (targetId = 24 AND aType IN(1, 2, 3, 4, 5)))
ORDER BY id DESC;
I have try to use model()->findAllBySql($sql) and it works. But I want to make it using CDbCriteria, if you have another solutions let me know it :D
You could still build this statement with a CDbCriteria I think... something like:
$criteria=new CDbCriteria;
$criteria->condition = '
(
(
userId = 1 OR
userId IN (SELECT userId FROM follower WHERE followerId = 1)
)
AND activityType IN(1, 2, 3)
)
OR (
targetId = 24
AND aType IN(1, 2, 3, 4, 5)
)
';
$criteria->order = 'id DESC';
$results=Activity::model()->findAll($criteria);
As this point you might as well just write a regular SQL statement, but there might be some benefits to doing it this way: binding params, merging criteria, adding additional criteria, etc.
As long as your plain SQL works, you're safe. There are many times when I have to throw Active Record away and just get the job done in the ol' saner way.
I tried to translate this query into a readable CDbCriteria construction. Bad idea. Yii sucks when it comes to query complex data.
The answer can be found here:
http://www.yiiframework.com/doc/guide/1.1/en/database.dao#executing-sql-statements
In your case:
$sql = 'SELECT * FROM activity';
$sql .= 'WHERE (((userId = 1 OR userId IN(SELECT userId FROM follower WHERE followerId = 1))';
$sql .= 'AND activityType IN(1, 2, 3))';
$sql .= 'OR (targetId = 24 AND aType IN(1, 2, 3, 4, 5)))';
$sql .= 'ORDER BY id DESC';
$connection = Yii::app()->db;
$command = $connection->createCommand($sql);
$results = $command->queryAll();
#pestaa is right that sometimes you have to throw active record out the window. This is especially true if you're doing mass updates where looping through numerous models is horribly inefficient.
Just use CSqlDataProvider
http://www.yiiframework.com/doc/api/1.1/CSqlDataProvider
Disclaimer: I know it's not precise answer to this particural question but it might help work around the problem that was given. I suspect the main purpose of this question is getting way to use CGridView, CListView etc. with arbitrary SQL.
I use CDbCriteria for complex queries in which I use the with feature.
You can build complex criteria like this:
$dbCriteria->with=array(
'<relation1>'=>array( 'condition'=>'<condition for given relation>',
'with'=>array('<relation2:relation of relation1>'
=>array(<conditions for relation2>)
)
'scopes'=><scopes for relation1>
)
);
I have not checked how OR can get into play here.
By using scopes, you can also insert some more complex criteria and still keep your search condition readable.
This is pretty powerful. I didn't see a complete 'tutorial' about this yet; I kind of concluded this from the source code.
Related
I have three tables: "users", "posts", and "likes" almost formatted as:
For example the three table entries are:
users (two users): 1. uid: 12,
2. uid: 15.
, and
posts (three posts): 1. pid: 3, publisherId = 12, likers = 2,
2. pid: 6, publisherId = 12, likers = 0,
3. pid: 7, publisherId = 12, likers = 1.
, and
likes (three likes): 1. lid: 1, postId = 3, likerId = 12,
2. lid: 2, postId = 7, likerId = 15,
3. lid: 3, postId = 3, likerId = 15.
What I need is: To get all the posts in a multi dimensional array with an array for the unique publisher (user) and another array for the likers (users also). The output I am looking for is something like:
Array: (
post:(
pid = 3,
publisher = Array (uid = 12),
likers = Array (uid=12, uid=15)
),
post:( ....
)
).
I am already getting that with the following time consuming (I believe):
$sql = "SELECT dev_posts.* FROM posts";
if (!$result = mysql_query($sql)) die("Query failed.");
$response = array();
while($result_array = mysql_fetch_object($result)) {
$entries = array();
foreach($result_array as $key => $value) {
if ($key == "byUserId") {
$publisherID = $result_array->byUserId;
$anotherSql = "SELECT * FROM users WHERE users.uid = $publisherID";
if ($anotherResult = mysql_query($anotherSql)) {
$anothers = array();
while($anotherResult_array = mysql_fetch_object($anotherResult)) {
$another = array();
foreach($anotherResult_array as $anotherKey => $anotherValue) {
$another[$anotherKey] = $anotherValue;
}
$anothers[] = $another;
}
$entries[$key] = $anothers;
}
}
else if ($key == "likes") {
if ($value > 0){
$PID = $result_array->pid;
$anotherSql = "SELECT likes.*, users.* FROM likes LEFT JOIN users ON likes.likeUserId = users.uid WHERE $PID = likes.likePostId";
if ($anotherResult = mysql_query($anotherSql)) {
$anothers = array();
while($anotherResult_array = mysql_fetch_object($anotherResult)) {
$another = array();
foreach($anotherResult_array as $anotherKey => $anotherValue) {
$another[$anotherKey] = $anotherValue;
}
$anothers[] = $another;
}
$entries[$key] = $anothers;
}
}
else {
$entries[$key] = array();
}
}
else {
$entries[$key] = $value;
}
}
$posts[] = $entries;
}
Any suggestions are appreciated. I am still looking for join and left join solutions!
it really depends on what you're looking for:
user data for all posts:
SELECT user.*, post.*
FROM post
LEFT JOIN user ON (post.publisherid=user.id)
since it's only one publisher per post, this should give the user's data for each and every post.
liker ids
SELECT post.*, GROUP_CONCAT(likes.likerid) as likerids
FROM post
LEFT JOIN likes ON (likes.postid=post.pid)
GROUP BY post.pid
this will give you rows:
["pid" => 3, "publisherid" => 12, "likerids" => "15,17,19"]
and all you have to do in php then is:
$likerids = explode(',', $row['likerids']);
combine for fun and profit
of course, you can combine both queries into one. However, the second query only works well, if you only need the ids of likers. If you want the user data as well, it might be good, (depending on your actual use case), to collect the likerids first and fetch their user data later
SELECT *
FROM user
WHERE user.uid IN (15,17,19)
Also, you should REALLY REALLY REALLY use prepared statements to protect against sql injections. (this is not bold by accident! this is important) If you don't know what sql injections are, read it up. If anyone finds a query that's vulnerable to user provided input and sql injections, all your users' data can (and most likely will) leak into the darkness that is the internet.
Also, please use pdo or mysqli libraries for your database queries. the mysql library is deprecated and is gone in 7.[something] I believe.
update
There are a bunch of problems associated with fetching both sides of an m:n relation. I mean, essentially it's easy, just fetch it:
SELECT post.*, user.*
FROM post
LEFT JOIN likes ON (post.pid=likes.postid)
LEFT JOIN user ON (likes.likerid=user.uid)
ORDER BY post.pid
however, this will produce these rows:
pid1, publisherid1, userid1, username1
pid1, publisherid1, userid2, username2
...
pid2, publisherid2, userid1, username1
...
as you will notice, the post itself appears multiple times, once for each liker. This is a problem, which cannot be avoided by standard sql alone, because of the fundamentals of sql (being row-based).
This is essentially the data you want, but I suppose in a more aggregated form. This form also contains lots and lots of redundant data, especially assuming the post data is way bigger than the user data. To gather the data, you would have to check the pid for every row, if it's the same pid as in the row before, you somehow merge the records. ... But I would strongly advise against this approach.
I would also advise against using GROUP_CONCAT for every single field of user, although it might work. The problem is, that GROUP_CONCAT needs a delimiter, which YOU need to be different from any character in the username field (or any other field, you want to retrieve). This might or might not be a problem, but it's dirty nonetheless. In any case, you then would have to explode every of those aggregated fields in php, rebuild the users' data to build your wanted structure.
Another solution might be, to create a new field, that holds aggregated userdata as json or something, and with the intelligent use of GROUP_CONCAT and CONCAT one could create a hierarchical string for each row, that could be json itself. But this goes beyond this post. (Also I condone such use of databases that aren't made nor designed for this). There is however a JSON data type, that could be interesting ...
Ultimately, in those cases, you let the database server do the work that IMHO should be done by the client.
I would do this:
two queries, for limited number of users (because YAGNI)
first we're going to fetch the posts we want, we also add a count for likes and the publisher's user data are included as well (if you add a WHERE with data, that comes from outside the server like a browser, use prepared statements! also read up on SQL, if you don't understand all or parts of this query!) - I would assume, this is all the data you would show to a user at first. (With the power of caching, showing likers for distinct posts could be quite efficient.)
$pdo = new PDO('#yourdatabasestring#'); // rtfm!
$postresult = $pdo->query(
'SELECT p.*, '.
' pub.uid, pub.username, '.
' COUNT(likers.uid) as likecount '.
'FROM post p '.
'LEFT JOIN user as pub ON (pub.uid=post.publisherid) '.
'LEFT JOIN likes ON (post.pid=likes.postid) '.
'LEFT JOIN user as likers ON (likers.uid=likes.likerid) '
'GROUP BY p.pid '.
'LIMIT 50' // learn about offsets!!!
);
now, put all results into an array
$pids = []; // this will contain post ids for which we want to fetch likes
$posts = [];
while($post = $postresult->fetch()) {
$pids[] = $post['pid'];
$post['likers'] = []; // prepare for later
$posts[$post['pid']] = $post;
}
At this point, this array only contains the data, that was requested in the first query (post, user data of publisher). Next, we query for the likes, we use the temporarily stored post ids.*
$likers = $pdo->query(
'SELECT likes.postid, user.* '.
'FROM likes '.
'LEFT JOIN user ON (likes.likerid=user.uid) '.
'WHERE likes.postid IN ('.implode(',', $pids).')'
);
and fetching them and assigning them to the right post.
while($like = $likers->fetch()) {
$posts[$like['postid']]['likers'][] = $like;
}
now ... this solution should actually work for almost every sql database. GROUP_CONCAT doesn't provide any benefit here. Two queries are actually quite alright here. If you have a very large set of posts that you want to fetch at once, this might absolutely not be the right approach. For fairly small data sets (some hundred posts or so), this should be very much okay.
*) the WHERE clause could be replaced by WHERE postid IN ([first query with only poist.pid in select]). For certain use cases, this could be preferable.
word of advice
However, for the usual web case, I can't imagine anyone wanting to see more than 50 posts at once with already displayed userdata, likers' data and stuff. don't try to show everything at once. fetch what's necessary, try to cluster information (as I did with the $pids) to reduce the number of queries. Doing a few well-designed and short-running queries in general beats doing many queries (as in your original code), but also is more appropriate than running one huge query, where most data will (on average) be irrelevant.
I want to check in mysql if all given keys exists in set or not. like:
$comma_separted_user_ids = "20,2,9,8,31,1";
$query ="SELECT conversation_id FROM message
WHERE FIND_IN_SET($comma_separted_user_ids, user_ids) ";
// data of user_ids = "1,2,8,9,20,31";
I want to check if all user id exist in user_ids column or not, user_ids are not properly ordered.
Please suggest a solution, thanks.
While it is technically feasible:
$query =
'SELECT conversation_id FROM message'
. 'WHERE FIND_IN_SET('
. str_replace(
',',
', user_ids) AND FIND_IN_SET('
$comma_separted_user_ids
)
. ', user_ids)' ;
... you should never do this!
Instead, create a new table to model the many-to-many relationship that exists between your user and message entities (e.g. participant). This is basic normalisation.
Then the query becomes trivial and performant:
SELECT conversation_id FROM participant
WHERE user_id IN ($comma_separted_user_ids)
GROUP BY conversation_id
HAVING COUNT(user_id) = [number of items in $comma_separted_user_ids]
Since you don't know the ordering, I don't see a way around FIND_IN_SET. Like others said, it'd be far better to normalise your table structure.
But in the interest of providing an answer to the question, you'll need to create a list of FIND_IN_SET operators.
// A list of IDs.
$comma_separated_user_ids = "20,2,9,8,31,1";
// The TRUE string will make sure that the array
// always contains at least one item.
$where = array("TRUE");
// Iterate over the IDs and create strings such as
// "FIND_IN_SET(1, column_name_here)"
foreach(explode(",", $comma_separated_user_ids) as $id) {
$where[] = "FIND_IN_SET($id, user_ids)";
}
Then it's a simple matter of joining the strings together:
// Join everything together with AND (&&).
// Since "0" is considered FALSE, this works.
$where = implode(" && ", $where);
// Query for rows.
$query ="SELECT conversation_id FROM message WHERE ($where) ";
Don't use this if you don't need to. It won't scale very well.
You can do this:
SELECT conversation_id
FROM message
WHERE FIND_IN_SET($comma_separted_user_ids, user_ids) > 0
GROUP BY conversation_id
HAVING count(distinct user_id) = 1 + (length($comma_separted_user_id) - length(replace($comma_separted_user_id, ',', '')))
The having clause is counting the number of elements in the comma separated list.
If you are creating the SQL, you should consider using a table to store the values instead of a list. A join approach can take advantage of indexes, which find_in_set() cannot.
i guess you should write it like this :
$comma_separted_user_ids = "20,2,9,8,31,1";
$query ="SELECT conversation_id FROM message
WHERE user_id IN ($comma_separted_user_ids) ";
Is it possible to do this sort of query in zend frameowrk?
SELECT *
FROM `relations`
WHERE (root_type, root_id) IN ( ("PRJ", 12), ("PRJ", 13), ("GRP", 42))
I only found a way to make a query with a IN clause on one column but not on two columns.
You can JOIN them instead, like this:
SELECT r.*
FROM relations r
INNER JOIN
(
SELECT 'PRJ' AS root_typ, 12 AS root_id
UNION ALL
SELECT 'PRJ', 13
UNION ALL
SELECT 'GRP', 42
) AS t ON r.root_type = t.root_type
AND r.root_id = t.root_id;
This is a ZF1 query using Zend_Db_Statement:
//common way to aquire currently selected db adapter
$db = Zend_Db_Table::getDefaultAdapter();
//$db is the currently selected database adapter.
$stmt = $db->query(
SELECT * FROM `relations`
WHERE (root_type, root_id)
IN ( ("PRJ", 12), ("PRJ", 13), ("GRP", 42))
);
This answer is not intended to be snide. For complex database queries, Zend_Db_Statement is often the easiest/simplest/best way to perform the query.
If you would like an explanation more tailored to your needs, please provide more info on your structure. In Zend Framework (1 or 2) there are often many ways to accomplish any given task.
Part of my page I have lots of small little queries, probably about 6 altogether, grabbing data from different tables. As an example:
$sql_result = mysql_query("SELECT * FROM votes WHERE voted_on='$p_id' AND vote=1", $db);
$votes_up = mysql_num_rows($sql_result);
$sql_result = mysql_query("SELECT * FROM votes WHERE voted_on='$p_id' AND vote=0", $db);
$votes_down = mysql_num_rows($sql_result);
$sql_result = mysql_query("SELECT * FROM kids WHERE (mother_id='$p_id' OR father_id='$p_id')", $db);
$kids = mysql_num_rows($sql_result);
Would it be better if these were all grabbed in one query to save trips to the database? One query is better than 6 isn't it?
Would it be some kind of JOIN or UNION?
Its not about number of queries but amount of useful datas you transfer. If you are running database on localhost, is better to let sql engine to solve queries instead computing results in additional programs. The same if you are thinking about who should be more bussy. Apache or mysql :)
Of course you can use some conditions:
SELECT catName,
SUM(IF(titles.langID=1, 1, 0)) AS english,
SUM(IF(titles.langID=2, 1, 0)) AS deutsch,
SUM(IF(titles.langID=3, 1, 0)) AS svensk,
SUM(IF(titles.langID=4, 1, 0)) AS norsk,
COUNT(*)
FROM titles, categories, languages
WHERE titles.catID = categories.catID
AND titles.langID = languages.
example used from MYSQL Bible :)
If you really want to lower the number of queries, you can put the first two together like this:
$sql_result = mysql_query("SELECT * FROM votes WHERE voted_on='$p_id'", $db);
while ($row = mysql_fetch_array($sql_result))
{
extract($row);
if ($vote=='0') ++$votes_up; else ++$votes_down;
}
The idea of joining tables is that these tables are expected to have something in between (a relation, for example).
Same is for the UNION SELECTS, which are prefered to be avoided.
If you want your solution to be clean and scalable in future, I suggest you to use mysqli, instead of mysql module of PHP.
Refer to: mysqli::multi_query. There is OOP variant, where you create mysqli object and call the function as method.
Then, your query should look like:
// I use ; as the default separator of queries, but it might be different in your case.
// The above could be set with sql statement: DELIMITER ;
$query = "
SELECT * FROM votes WHERE voted_on='$p_id' AND vote=1;
SELECT * FROM votes WHERE voted_on='$p_id' AND vote=0;
SELECT * FROM kids WHERE (mother_id='$p_id' OR father_id='$p_id');
";
$results = mysqli_multi_query($db, $query); // Returns an array of results
Fewer queries are (generally, not always) better, but it's also about keeping your code clear enough that others can understand the query. For example, in the code you provided, keep the first two together, and leave the last one separate.
$sql_result = mysql_query("SELECT vote, COUNT(*) AS vote_count
FROM votes
WHERE voted_on='$p_id'
GROUP BY vote", $db);
The above will return to you two rows, each containing the vote value (0 or 1) and the vote count for the value.
I need to create native SQL query with couple of unions and subqueries. It'll look approximately like this:
SELECT res.id, COUNT(*) as count_ids
FROM (
SELECT a.id FROM ... a WHERE ... LIKE ('%:param%')
UNION ALL
SELECT b.id FROM ... b WHERE ... LIKE ('%:param%')
UNION ALL
...
) res
GROUP BY res.id
ORDER BY count_ids asc
Result won't match any Entity I use in my application. Is it possible to create ResultSetMapping with "anonymous" object? Or is it, at least, possible to create an Entity that wouldn't create table next time I update schema, so I can map results to it?
Or is there any other Doctrine-friendly way to deal with such query? Making changes to database isn't possible though, as I'm dealing with legacy stuff that cannot be touched. I'd also strongly prefer if I did everything on database side, not involving much of PHP in it.
Do you have a particular need to map results to a domain object? If not, you could use the DBAL to make a plain old query, which will return an array, as detailed in the Symfony2 cookbook and the Doctrine DBAL documentation:
$conn = $this->container->get('database_connection');
$sql = 'SELECT res.id, COUNT(*)...';
$rows = $conn->query($sql);
Use addScalarResult method of ResultSetMapping
$rsm = new ResultSetMapping();
$rsm->addScalarResult('cnt', 'cnt');
$rsm->addScalarResult('id', 'id');
$query = $this->em->createNativeQuery('SELECT count(*) AS cnt, id_column as id FROM your_table group by id', $rsm);
$result = $query->getResult();
var_dump($result);
Result array:
array (size=1)
0 =>
array (size=2)
'cnt' => int 1
'id' => int 15