My aim is to build a relationship between rooms, people and work shift. So my sequel string looks like this :
x = DB[:raum].join_table(:left, DB[:platz], :rid => :id)
.join_table(:left, DB[:patient_behandlungs_link], :platz_id => :id)
.join_table(:left, DB[:patienten], :id => :patienten_id)
.join_table(:left, DB[:behandlungsverfahren], :id => :t2__behandlungsverfahren_id)
.join_table(:left, DB[:dialysezeit], :id => :t2__dialysezeit_id)
.join_table(:left, DB[:nadeln], :id => :t2__dialysenadel_id)
.join_table(:left, DB[:dialysatorzugang], :id => :t2__dialysatorzugang_id)
.where("raumnummer = ?", raumid.to_i)
It's working like this but in the resulting table there is also a field for the shift id. In this state it does not differentiate in which workshift the person is working. if i do a foreach and push the values out I get my empty nil fields with no one inside, which I want to, and I get the people which are in room raumid from all workshifts.
If I make a .filter(:schicht_id => 1) for example, then I loose my nil values. I need them to assign new people to the empty slots, so I tried (:schicht_id => 1).or(:schicht_id => nil) and similar things but I don't get my result, I want
I think i blamed sequel for something that is not related to sequel.
In the image my select box starts showing options from the second value
This behavior made me think, something was wrong with my joins and group by instructions.... i now have to figure out why the select box shows me from values form 2-9 and not from 1-9. In the HTML Site Source code all 9 Options are given.
This is strange for me.
sorry for blaming sequel.
Related
I have a model named Application. And Application is associated to has_many model named Location.
Application has many Location
In my Application query:
$this->Application->find('all', array('conditions' => 'Application.status' => 'accepted'));
I'm finding applications where status is accepted.
Next thing that I would like to achieve is to find Application records where associated Location is empty/null or in other words where count of Location records is 0.
I tried to make join query like this:
$join_query = array(
'table' => 'locations',
'alias' => 'Location',
'type' => 'INNER',
'conditions' => array(
'Location.application_id = Application.id',
'OR' => array(
array('Location.id' => NULL)
)
)
);
But seems like it's just querying Application records that do have associated Location records.
Thanks in advanced if you guys have any idea(s).
You need to use a left join, not an inner join. Inner join will get only those results that have a row in both of the tables you are joining, where you want only results where there is only a row in the left table. Left joins will get all the results in the left table, regardless if there's a row associated with it in the right table. Then add a condition after the join is complete, to only select those joined results where Location.id is null.
$this->Application->find('all',
array(
'conditions' => array('Location.id' => null),
'joins' => array(
array(
'table' => 'locations',
'alias' => 'Location',
'type' => 'LEFT',
'conditions' => array('Location.application_id = Application.id')
),
),
)
);
Your query says "find any application and its location with application_id = id, AND (1 OR where location.id = null)", so that will match any application that has location.
What I'd do is to leave joins and just use containable and counts. With plain sql I'd use a left join and count the Locations, like in this example. But cake doesn't behave well with not named columns, like "COUNT(*) AS num_locations", so I tend to avoid that.
I'd transform your query to a containtable one
$apps = this->Application->find('all', array('contains'=>'Location'));
foreach($apps as $app) {
if (count($app['Location']) <= 0)
//delete record
}
You could also implement a counterCache, and keep in a BD column the number of locations per application, so the query can be a simple find like
$this->Application->find('all', array('conditions'=>array('location_count'=>0)));
Ooooor, you could add a virtual field with "SUM(*) as num_locations" and then use your join with "left outter join" and compare "num_locations = 0" on the conditions.
Those are the options that comes to mind. Personally I'd use the first one if the query will be a one time/not very used one. Probably put it in the Application model like
public function findAppsWithNoLocations() {
$apps = this->Application->find('all', array('contains'=>'Location'));
foreach($apps as $app) {
if (count($app['Location']) <= 0)
//delete record
}
}
But the other two options would be better if the sum of locations per app is going to be a recurrent query you'll search for.
EDIT
And of course Kai's answer options that does what you want xD. This tendency to complicate things will be the end of me... Well, will leave the answer here to show a reference to other convoluted options (specifically counterCache if you'll need to count the relations a lot of times).
i know this is already some time ago.
i could manage it this way:
public function getEmpty($assoc) {
foreach($this->find('all') as $c){
if(empty($c[$assoc])) $return[] = $c;
}
return $return;
}
now i got all entries that have an empty associated data.
in my controller i call the function like this:
$ce = $this->Company->getEmpty('CompaniesUsers');
companies Users is the Empty Associated model i want to check.
In a cakePHP application I am building, a profile can have multiple locations; the tables are called "profiles" and "locations" and in the model classes I have defined a HasMany relationship. Now I want the user to be able to search profiles based on their locations. After reading some questions here and the CakePHP Cookbook, I have decided I need to use SQL joins (in reality more tables are involved, and the result of a search should be based on conditions concerning different tables).
I have written the following function inside my Profile model:
public function findProfiles($long, $lat){
$options['joins'] = array(
array('table' => 'locations',
'alias' => 'Location',
'type' => 'Inner',
'conditions' => array('Location.profile_id = Profile.id'))
);
$options['order'] = array('Location.lng ASC'); //this is just as trial
return $this->find('all',$options);
}
The code works, but I get a copy of a profile for each location it possesses. That is, if a profile possesses 5 positions, I get five instances of that profile (each instance containing all five positions!)
How can I achieve this?
[edit]
eg. let's assume I only have one profile, with two positions. I get:
result[0][Profile]
[Position][0]
[1]
[1][Profile]
[Position][0]
[1]
Where the data in result[0] and result[1] is identical.
The problem happens because of the type of join used. With inner join you'll get this return with your query
profile_id location_id
---------------------------
1 2
1 3
And cake understands that as two records of Profile, so you get repeated Profiles with the same info.
If this were all the extent of your problem, I'd say "go with Containable behaviour and forget joins", but since you said there are more tables involved, maybe the type of join can't be changed. So to get the unique Profile without repetitions, you'll have to GROUP BY the query to get
profile_id location_id
---------------------------
1 2 & 3
with a code similar to this
$options['joins'] = array(
array('table' => 'locations',
'alias' => 'Location',
'type' => 'Inner',
'conditions' => array('Location.profile_id = Profile.id')),
'group' => 'Profile.id'
);
and you'll get rid of repetitions. For future problems like this, is best to first check the actual query that gets send to the DB, check yourself if the result that the DB gives you is what you want, and if not, see what you can do in cake to change it.
I am working in Rails 2.3.x on a learning management system. Here's my code:
-#users.each do |user|
%tr
%td
=link_to h(user.name), :action => :show_user, :id => user.id
%td="#{h user.grade_level}"
-if QuizResult.find_by_user_id(#user_id).present?
="#{(QuizResult.average('score', :conditions => 'user_id = #{#user.id}') * 100).round}%"
-else
%em No quizzes taken
My quiz_results table has columns for user_id and score, among others. I have a record with a user_id (3907) and result (0.1), and two users I'm looking at with no records in the quiz_results table.
The display says "No quizzes taken" for all three, which leads me to believe that this line is false no matter what:
-if QuizResult.find_by_user_id(#user_id).present?
Any ideas how to fix?
Change #user_id to user.id in the if statement and #user.id to user.id. Also change the single quotations to double quotations or using string interpolation won't work.
I guess you need to change #user.id to user.id.
As the answer to second part of your question, I think you can't have a nested evaluated string (the nested #{}). You need to compute the results first, then evaluate and output it in HAML:
-averge = QuizResult.average('score', :conditions => 'user_id = #{#user.id}') * 100).round
="#{average}%"
I'm making this query to MySql
Image.find( :all,
:conditions => ["created_at > ? && approved = 1", #image.created_at],
:order => "created_at DESC", :limit => 5)
However, I want the images create just before the given image was created at. Right now, it's returning a list of images from the top of the list, that were create much, much before that image. How can I do this?
Your current query will find any images newer than #image because your using >. You'll need to decide what kind of range you're wanting to look in.. What time frame do you consider "just before"? Minutes? Seconds?
To find all images created within 5 mins of #image, try:
Image.find(:all, :conditions => ["(created_at > ? and created_at < ?) and approved = 1", #image.created_at.advance(:minutes => -5), #image.created_at])
My solution feels more like a hack, but I'm not sure of a better one. I set :order => "created_at ASC"... and then reversed the resulting array, and got the response I wanted. Hrm.
When querying the database with:
#robots = Robot.all(:condition => [:a => 'b'], :limit => 50, :offset => 0)
What is the best way to get the total number of rows without the :limit?
In raw MySQL you could do something like this:
SELECT SQL_CALC_FOUND_ROWS * FROM robots WHERE a=b LIMIT 0, 50
SELECT FOUND_ROWS();
Is there an active record way of doing this?
This works for me:
ps = Post.all(:limit => 10, :select => "SQL_CALC_FOUND_ROWS *")
Post.connection.execute("select found_rows()").fetch_hash
=> {"found_rows()"=>"2447"}
This will probably not work for joins or anything complex, but it works for the simple case.
Robot.count actually is the solution you want.
Reading one of the comments above, it looks like you may have a misunderstanding of how .count works. It returns a count of all the rows in the table only if there's no parameters.
but if you pass in the same conditions that you pass to all/find eg:
Robot.count(:conditions => {:a => 'b'})
.count() will return the number of rows that match the given conditions.
Just to be obvious - you can even save the condition-hash as a variable to pass into both - to reduce duplication, so:
conds = {:a => 'b'}
#robots = Robot.all(:conditions => conds, :limit => 50)
#num_robots = Robot.count(:conditions => conds)
That being said - you can't do an after-the-fact count on the result-set (like in your example). ie you can't just run your query then ask it how many rows would have been found. You do actually have to call .count on purpose.
search = Robot.all(:condition => ["a=b"], :offset => 0)
#robots = search[0..49]
#count = search.count
That should get what you want, gets all the Robots for counting and then sets #robots to the first 50. Might be a bit expensive on the resource front if the Robots table is huge.
You can of course do:
#count=Robot.all(:condition => ["a=b"], :offset => 0).count
#robots=Robot.all(:condition => ["a=b"], :limit => 50, :offset => 0)
but that will hit the database twice on each request (although rails does have query caching).
Both solutions only use active record so are database independent.
What do you need the total returned by the query for? if its pagination look into Will_paginate (Railscast) which can be extended with AJAX etc...
Try find_by_sql may that help.
Is #robots.size what you're looking for? Or Robot.count?
Otherwise, please clarify.
I think hakunin is right.
You can get no of row return by query by just chekcing the size of resulting array of query.
#robots = Robot.find_by_sql("Your sql")
or
#robots = Robot.find(:all , :conditions=>["your condiitons"] )
#robots.size or #robots.count