I'm having trouble creating a join in the codeigniter format, i have a MySQL query that returns what i want:
SELECT nwsite.siteid, nwsite.installer_username,
calcdata.esolar, calcdata.time, calcdata.wsolar
FROM nwsite, calcdata
WHERE nwsite.siteid = calcdata.siteid AND time = '2011-10-29 12:45:00';
I've looked at the documentation but i keep getting it wrong.
Thanks
From the CI docs...
$this->db->select('*');
$this->db->from('blogs');
$this->db->join('comments', 'comments.id = blogs.id');
$query = $this->db->get();
// Produces:
// SELECT * FROM blogs
// JOIN comments ON comments.id = blogs.id
So in your case, I would not use the cartisian product in your FROM, I would actually use a join.
$this->db->select("... your fields here...");
$this->db->from("nwsite");
$this->db->join("calcdata", "nwsite.siteid = calcdata.siteid");
$this->db->where("nwsite.time", "2011-10-29 12:45:00");
$query = $this->db->get();
For Future reference, I often utilize
die($this->db->last_query());
to output the actual query that's being generated. It makes it easier to debug and compare to what you are attempting to generate.
Related
Is there away to cross join from php. In example:
Currently I query a database like so:
$company_id = 20;
$templates_data = $this->db->select('template_id')
->from('dr_template_relational')
->where('dr_template_relational.company_id',$company_id)
->get()
->result_array();
What I'm looking to do is something like this:
->from('dr_template_relational')
->cross_join()
There's several responses to this question on SO but post reference a regular sql query like so:
"SELECT * FROM citys LEFT JOIN comments ON comments.city=citys.city WHERE citys.id=$id";
This would be the way to do it in SQL query but the point here is to do it in php and get the data returned with a cross join. I also realize the query can be made with in php to have it select the data and join it with code but my question is related to is there away to simply add ->cross_join() or something like that.
You can run raw query in codeigniter to solve your problem as below:
$sql 'your query here with cross join';
$query = $this->db->query($sql);
return $query->result_array();
Hope it helps you :)
You can use CI join method.
$company_id = 20;
$templates_data = $this->db->select('dr_template_relational.template_id')
->where('dr_template_relational.company_id',$company_id)
->join('table','dr_template_relational.company_id=table.company_id','LEFT')
->get()
->result_array();
where 'LEFT' is the join type
The following is my mysql query:
select * from db_posts LEFT JOIN db_followers ON db_posts_user_id = db_followers_following AND db_followers_user_id = 276
How can I convert it to codeigniter using query builder?
$this->db->where('db_posts_user_id', 'db_followers_following');
$this->db->where('db_followers_user_id', 276);
$this->db->order_by('db_posts.db_posts_id', 'DESC');
$this->db->join('db_followers', 'db_followers.db_followers_following = db_posts.db_posts_user_id');
$query2 = $this->db->get('db_posts')->result_array();
I get the required result when I use mysql query. But I get a blank array when I use codeigniter queries. What is wrong in my CI Query?
why are you using those where clause? if you are using it as condition for your 'JOIN' process, try it like this:
$this->db->order_by('db_posts.db_posts_id', 'DESC');
$this->db->join('db_followers', 'db_followers.db_followers_following = db_posts.db_posts_user_id and db_followers_user_id = 276', 'left');
$query2 = $this->db->get('db_posts')->result_array();
Points to Note
1)as previous comments said, you should 'Left Join' if you want to get all posts from 'db_posts'.
2) You can add Multiple conditions in ON Clause using and but within ''. all your conditions should be specified before second comma(,) which is before mentioning 'LEFT'.
Hope this will help. Lemme know if this help
Try adding the "Left" option to tell it what kind of join to do:
$this->db->join('db_followers', 'db_followers.db_followers_following = db_posts.db_posts_user_id', 'Left');
Also I'm not sure you need
$this->db->where('db_posts_user_id', 'db_followers_following');
this is already covered by your JOIN statement.
Source:
http://www.bsourcecode.com/codeigniter/codeigniter-join-query/#left-join and https://www.codeigniter.com/userguide3/database/query_builder.html
is it possible to pass the variable value in mysql query in codeigniter ?
I want to select records from database that have id same as my session id.
my code is :
$this->db->select('*'); // <-- There is never any reason to write this line!
$this->db->from('products');
$this->db->where('id_admin = (SELECT id_admin FROM users WHERE id='.$this->session->userdata('user_id').')', NULL, TRUE);
can we concatenate variable values in database queries?
This code not given any error, but not give any result also.
Use join in active records
$this->db->select('p.*');
$this->db->from('products as p');
$this->db->join('users','p.id_admin=users.id');
$this->db->where('users.id',$this->session->userdata('user_id'),false);
$query = $this->db->get();
An Example Reference of how to write the JOIN Query in CI as per the Documentation of the Active Records.
$article_id = $this->input->post('article_id');
$this->db->select('*');
$this->db->from('articles');
$this->db->join('news', 'news.id = articles.id');
$this->db->where('articles.id',$article_id);
$query = $this->db->get();
The above code will produce the query as follows for execution.
SELECT * FROM articles JOIN news ON news.id = articles.id WHERE articles.id='10'
Provided the passed id is 10
In order to view the Result of the executed query you must perform the below code.
print_r($query->result());
Try like this..use joining of two tables.
<?php
$this->db->select('products.*');
$this->db->from('products');
$this->db->join('users','products.id_admin=users.id_admin');
$this->db->where('users.id',$this->session->userdata('user_id'));
$query = $this->db->get();
print_r($query->result_array());//your array of records
I have a table with this structure:
opinion_id, author_id, title, content
I would like to get all the latest records from the table, one record for author, that means the latest record for every author...
My distinct function does not seem to be working...
function getOpinions() {
$data = array();
$this->db->select('*');
$this->db->from('opinions');
$this->db->join('authors', 'opinions.author_id = authors.author_id');
$this->db->order_by('date', 'desc');
$this->db->distinct('author_id');
$Q = $this->db->get();
if ($Q->num_rows() > 0) {
foreach($Q->result_array() as $row) {
$data[] = $row;
}
}
$Q->free_result();
return $data;
}
In Codeigniter, distinct does not work the way you expect it by field name. If you look at the manual - there is no argument for distinct. If you look at the code, it only takes a boolean, which defaults to true. It just adds the DISTINCT keyword to the query after the SELECT keyword. That's it.
In your case, I think it would be better to use a GROUP BY as in
$this->db->group_by('opinions.author_id');
Hopefully the order by would work as per your need in this instance by ordering before the grouping.
Cheers!
EDIT - update after OP comments
I know the ordering can be messed up - I sort of mentioned it :)
Anyway, I might be assuming some of your table structure here, but this would force the GROUP BY to pick the rows on the top. I assume that the date is on the opinions table and you only want the latest row from that with author details.
SELECT * FROM `authors`
JOIN (
SELECT * FROM opinions
ORDER BY `date` DESC
) AS ops ON ops.author_id = authors.author_id
GROUP BY ops.author_id
You will not be able to construct this query on active record though. Hope this helps.
I wanted to use the CI Active Record methods to perform this query, but it gives me different results than if I execute the query in plain SQL. This is the query:
SELECT B.id as id
FROM default_log_workout A, default_log_workout B
WHERE A.id=$id AND B.completed < A.completed AND A.workout_id=B.workout_id
ORDER BY B.completed desc
LIMIT 1
CodeIgniter:
$this->db->select("B.id as id");
$this->db->from("log_workout A, log_workout B");
$this->db->where(array("A.id" => $id, "B.completed < A.completed", "A.workout_id=B.workout_id"));
$this->db->order_by("B.completed desc");
$this->db->limit(1);
$res = $this->db->get();
The query should return the next older row based on a given "id". The plain SQL works, the CI calls end up returning the OLDEST row, not the next oldest. I figure it's just a syntax error in my CI calls... but I can't figure it out. I've since moved on to solve the problem with $this->db->query("the SQL") but this is still bugging me.
Anyone know why the CI version doesn't work?
The ORDER BY clause should have two parameters:
$this->db->order_by('B.completed', 'DESC');
I'm not sure if Active Record will parse your comma separated table string in your from() clause. I suggest rewriting it in an ANSI standard from ... join ... on syntax.
$this->db->select("B.id as id");
$this->db->from("log_workout A");
$this->db->join("log_workout B","A.workout_id = B.workout_id AND B.completed < A.completed");
$this->db->where("A.id" => $id);
$this->db->order_by("B.completed", "desc");
$this->db->limit(1);
$res = $this->db->get();
And, as Yan pointed out, the order by should have two parameters.