I am having a problem with Mysql join. I have two tables, a center_contacts table and a center_contacts_notes. center_contacts_notes are linked via a contact_id that is found in both tables.
Inside of center_contacts_notes there can be multiple rows per contact_id and I want to grab all of these and put them in a sub array of the results.
For example, here is what my center_contacts_notes table looks like:
contact_id | note
------------------------
1 test
2 hello
3 sup
1 moo
Here is where I am attempting to grab the data:
$this->db->select('center_contacts.id, FirstName, LastName, center_contacts_notes.note');
$this->db->from('center_contacts');
$this->db->join('center_contacts_notes', 'center_contacts_notes.contact_id = center_contacts.id');
Note that I am using Codeigniter 3.
Here is what I get from this:
Array
(
[id] => 1
[FirstName] => Bob
[LastName] => Smith
[note] => test
)
Array
(
[id] => 1
[FirstName] => Bob
[LastName] => Smith
[note] => moo
)
These are two different arrays inside of my results. This is impractical for my use as I need one array that contains both notes. Something like this:
Array
(
[id] => 1
[FirstName] => Bob
[LastName] => Smith
[note] => Array(test, moo)
)
Is this possible, and if so how would I accomplish it? Thanks.
I don't know if you can get the two dimensional array like you've mentioned, but there is a workaround to get similar results. This might be helpful to you.
What you need to do is use Group By and group_concat(). Group by the table by contact_id and apply group_concat() on center_contacts_notes.note.
Your query should look like this.
$this->db->select('center_contacts.id, FirstName, LastName, GROUP_CONCAT(center_contacts_notes.note)');
$this->db->from('center_contacts');
$this->db->join('center_contacts_notes', 'center_contacts_notes.contact_id = center_contacts.id');
$this->db->group_by('center_contacts.id');
By default group_concat will concat the column by ,. You can change it the following way.
GROUP_CONCAT(center_contacts_notes.note SEPARATOR 'YOUR_SEPARATOR_STRING')
This will return result as follow:
Array
(
[id] => 1
[FirstName] => Bob
[LastName] => Smith
[note] => test[YOUR_SEPARATOR_STRING] moo
)
You can use PHP explode to convert note string into array by providing separator value.
Related
I'm facing one problem and I can't find the perfect and best optimized solution.
So I'm kindly asking for your opinion.
Here's what bothering me.
I've got a serialized array from DB that looks like this:
a:6:{s:13:"property_type";s:1:"1";s:16:"property_feature";a:2:{i:0;s:1:"3";i:1;s:1:"4";}s:19:"property_offer_type";s:1:"5";s:19:"property_built_type";a:1:{i:0;s:2:"10";}s:24:"properties_office_phones";s:2:"13";s:15:"property_labels";a:1:{i:0;s:1:"8";}}
Here is the non-serialized version for more clarity:
Array(
[property_type] => 1
[property_feature] => Array
(
[0] => 3
[1] => 4
)
[property_offer_type] => 5
[property_built_type] => Array
(
[0] => 10
)
[properties_office_phones] => 13
[property_labels] => Array
(
[0] => 8
))
All of this keys values are stored in one single table.
This is how the table looks like:
ID | Name | Slug | .. etc
1 | A name here | a-name-here | .. other
What do you think will be the best and most optimized way to get the information related to those IDs using Laravel 8 relations, so it can be retrieved as relations just like "with()" is doing.
Thanks in advance!
I have 2 tables in a database, 1 of them are linked with a foreign key to the first one. Each row on table 1 is linked to multiple rows in table 2. I am trying to make a query that looks at a WHERE from table 2 and returns multiple rows from table 2 which are sorted into the rows they linked with in table 1 and then put this all into one big multi dimensional array, so it should work something like this:
$array[0][column_name][0] this would use row 1 from table 1 and give me a the first result in the column called column_name
$array[1][column_name][0] this would use row 2 from table 1 and give me a the first result in the column called column_name
$array[1][column_name][3] this would use row 2 from table 1 and give me a the 4th result in the column called column_name
etc
How can I query this and store it in a 3 dimensional array using PHP.
I have tried to word this in as clear manner as possible, if you are unsure what I am asking, please comment and I will update my question to make it clearer.
Assume that we have two tables, Company and Employee:
Company
------------------
ID Company_Name
1 Walmart
2 Amazon.com
3 Apple
Employee
---------------------------------
ID Company_Id Employee_Name
1 1 Sam Walton
2 1 Rob Walton
3 1 Jim Walton
4 1 Alice Walton
5 2 Jeff Bezos
6 2 Brian T. Olsavsky
7 3 Steve Jobs
8 3 Tim Cook
The easiest way to envision a multi-dimensional (nested) array is to mimic the looping required to get it: outer loop is the company, inner loop is the employees:
// ignoring database access, this is just pseudo code
$outer = [];
// select id, company_name from company
foreach $companyResult as $companyRow {
// select * from employee where company_id = ? {$companyRow['id']}
$inner= [];
foreach $employee_result as $employeeRow {
$inner[] = $employeeRow; // ie, ['id'=>'1','Company_Id'=>'1','Employee_Name'=>'Sam Walton']
}
$outer[] = $inner;
}
print_r($outer);
// yields ====>
Array
(
[0] => Array
(
[0] => Array
(
[id] => 1
[Company_Id] => 1
[Employee_Name] => Sam Walton
)
[1] => Array
(
[id] => 2
[Company_Id] => 1
[Employee_Name] => Rob Walton
)
[2] => Array
(
[id] => 3
[Company_Id] => 1
[Employee_Name] => Jim Walton
)
[3] => Array
(
[id] => 4
[Company_Id] => 1
[Employee_Name] => Alice Walton
)
)
[1] => Array
(
[0] => Array
(
[id] => 5
[Company_Id] => 2
[Employee_Name] => Jeff Bezos
)
[1] => Array
(
[id] => 6
[Company_Id] => 2
[Employee_Name] => Brian T. Olsavsky
)
)
[2] => Array
(
[0] => Array
(
[id] => 7
[Company_Id] => 3
[Employee_Name] => Steve Jobs
)
[1] => Array
(
[id] => 8
[Company_Id] => 3
[Employee_Name] => Tim Cook
)
)
)
It is also possible to do if you use associative arrays. Consider the flat file that this query produces:
select company.id company_id, company.name company_name,
emp.id employee_id, emp.employee_name
from company
inner join employee on company.id = employee.company_id
-----
company_id company_name employee_id employee_name
1 Walmart 1 Sam Walton
1 Walmart 2 Rob Walton
1 Walmart 3 Jim Walton
1 Walmart 4 Alice Walton
2 Amazon.com 5 Jeff Bezos
2 Amazon.com 6 Brian T. Olsavsky
3 Apple 7 Steve Jobs
3 Apple 8 Tim Cook
Just use the primary IDs as the keys for your arrays:
$employeeList = [];
foreach($result as $row) {
$cid = $row['company_name'];
$eid = $row['employee_name'];
// avoid uninitialized variable
// $employeeList[$row['company_name']] = $employeeList[$row['company_name']] ?? [];
// easier to read version of above
$employeeList[$cid] = $employeeList[$cid] ?? [];
// assign it...
$employeeList[$cid][$eid] = $row;
}
Or, if you simply want each company row to hold an array of employee names,
$employeeList[$cid][] = $row['employee_name'];
The way that I've shown you is useful if you know the company_id and want to find the associated rows:
foreach($employeeList[2] as $amazon_guys) { ... }
But it's not at all useful if you're trying to group by employee, or some other field in the employee table. You'd have to organize the order of your indexes by your desired search order.
In the end, it's almost always better to simply do another query and let the database give you the specific results you want.
I’ve seen the following question on StackOverflow, Intelligent MySQL GROUP BY for Activity Streams posted by Christian Owens 12/12/12.
So I decided to try out the same approach, make two tables similar to those of his. And then I pretty much copied his query which I do understand.
This is what I get out from my sandbox:
Array
(
[0] => Array
(
[id] => 0
[user_id] => 1
[action] => published_post
[object_id] => 776286559146635
[object_type] => post
[stream_date] => 2015-11-24 12:28:09
[rows_in_group] => 1
[in_collection] => 0
)
)
I am curious, since looking at the results in Owens question, I am not able to fully get something, and does he perform additional queries to grab the actual metadata? And if yes, does this mean that one can do it from that single query or does one need to run different optimized sub-queries and then loop through the arrays of data to render the stream itself.
Thanks a lot in advanced.
Array
(
[0] => Array
(
[id] => 0
[user_id] => 1
[fullname] => David Anderson
[action] => hearted
[object_id] => array (
[id] => 3438983
[title] => Grand Theft Auto
[Category] => Games
)
[object_type] => product
[stream_date] => 2015-11-24 12:28:09
[rows_in_group] => 1
[in_collection] => 1
)
)
In "pseudo" code you need something like this
$result = $pdo->query('
SELECT stream.*,
object.*,
COUNT(stream.id) AS rows_in_group,
GROUP_CONCAT(stream.id) AS in_collection
FROM stream
INNER JOIN follows ON stream.user_id = follows.following_user
LEFT JOIN object ON stream.object_id = object.id
WHERE follows.user_id = '0'
GROUP BY stream.user_id,
stream.verb,
stream.object_id,
stream.type,
date(stream.stream_date)
ORDER BY stream.stream_date DESC
');
then parse the result and convert it in php
$data = array(); // this will store the end result
while($row = $result->fetch(PDO::FETCH_ASSOC)) {
// here for each row you get the keys and put it in a sub-array
// first copy the selected `object` data into a sub array
$row['object_data']['id'] = $row['object.id'];
$row['object_data']['title'] = $row['object.title'];
// remove the flat selected keys
unset($row['object.id']);
unset($row['object.title']);
...
$data[] = $row; // move to the desired array
}
you should get
Array
(
[0] => Array
(
[id] => 0
[user_id] => 1
[fullname] => David Anderson
[verb] => hearted
[object_data] => array (
[id] => 3438983
[title] => Grand Theft Auto
[Category] => Games
)
[type] => product
[stream_date] => 2015-11-24 12:28:09
[rows_in_group] => 1
[in_collection] => 1
)
)
It seems that you want a query where you can return the data you're actually able to get plus the user fullname and the data related to the object_id.
I think that the best effort would be to include some subqueries in your query to extract these data:
Fullname: something like (SELECT fullname FROM users WHERE id = stream.user_id) AS fullname... or some modified version using the stream.user_id, as we can't identify in your schema where this fullname comes from;
Object Data: something like (SELECT CONCAT_WS(';', id, title, category_name) FROM objects WHERE id = stream.object_id) AS object_data. Just as the fullname, we can't identify in your schema where these object data comes from, but I'm assuming it's an objects table.
One object may have just one title and may have just one category. In this case, the Object Data subquery works great. I don't think an object can have more than one title, but it's possible to have more than one category. In this case, you should GROUP_CONCAT the category names and take one of the two paths:
Replace the category_name in the CONCAT_WS for the GROUP_CONCAT of all categories names;
Select a new column categories (just a name suggestion) with the subquery which GROUP_CONCAT all categories names;
If your tables were like te first two points of my answer, a query like this may select the data, just needing a proper parse (split) in PHP:
SELECT
MAX(stream.id) as id,
stream.user_id,
(select fullname from users where id = stream.user_id) as fullname,
stream.verb,
stream.object_id,
(select concat_ws(';', id, title, category_name) from objects where id = stream.object_id) as object_data,
stream.type,
date(stream.stream_date) as stream_date,
COUNT(stream.id) AS rows_in_group,
GROUP_CONCAT(stream.id) AS in_collection
FROM stream
INNER JOIN follows ON 1=1
AND stream.user_id = follows.following_user
WHERE 1=1
AND follows.user_id = '0'
GROUP BY
stream.user_id,
stream.verb,
stream.object_id,
stream.type,
date(stream.stream_date)
ORDER BY stream.stream_date DESC;
In ANSI SQL you can't reference columns not listed in your GROUP BY, unless they're in aggregate functions. So, I included the id as an aggregation.
Questions
How should I do the query(ies) to get this results?
Should I use a different structure for database tables?
Details
I want to get results from 3 tables:
+------------------------------+-------------------+
| courses | id | <-------+
| | name | |
| | | |
+------------------------------+-------------------+ |
| sections | id | <-------|----------+
| | course_id | <- FK(courses.id) |
| | name | |
+------------------------------+-------------------| |
| resources | id | |
| | section_id | <- FK(sections.id)-+
| | name |
+------------------------------+-------------------+
I want to store results in a PHP Array like this:
Array
(
[courses] => Array
(
[id] => 1
[name] => course 1
[sections] => Array
(
[0] => Array
(
[id] => 1
[course_id] => 1
[name] => course 1 section 1
[resources] => Array
(
[0] => Array
(
[id] => 1
[section_id] => 1
[name] => resource 1
)
)
)
)
)
)
EDIT
What I did:
$cources = DB::query(Database::SELECT,
'select * from courses')->execute($db,false)[0]; // Get all courses as array
foreach($courses as &$course) {
$sections = DB::query(Database::SELECT,
'select * from sections where course_id = '.$courses['id']);
$course['sections'] = $sections;
foreach($course['sections'] as &§ion) {
$resources = DB::query(...); // Get array of resources
$section['resources'] = $resources;
}
}
The database structure is normalized - this is correct and should not be changed.
However, SQL returns de-normalized or "flattened" data for an N+ join: only a set of homogenous records can be returned in a single result-set. (Some databases, like SQL Server, allow returning structure by supporting XML generation.)
To get the desired array structure in PHP will require:
Separate queries/result-sets (as shown in the post): ick!
There will about one query/object. While the theoretical bounds might be similar, the practical implementation will be much less efficient and the overhead will be much more than for single query. Remember that every query incurs (at the very least) a round-trip penalty - as such, this is not scalable although it will likely work just fine for smaller sets of data or for "time insensitive" operations.
Re-normalize the resulting structure:
This is very trivial to do with support of a "Group By" operation, as found in C#/LINQ. I am not sure how this would be approached [easily] in PHP1. This isn't perfect either, but assuming that hashing is used for the grouping, this should be able to scale fairly well - it will definitely be better than #1.
Instead of the above, consider writing the query in such a way that the "flat" result can be used within the current problem/scope, if possible. That is, analyze how the array is to be used - then write the queries around that problem. This is often a better approach that can scale very well.
1 Related to re-normalizing the data, YMMV:
SQL result to PHP multidimensional array
PHP array to multidimensional array
Group a multidimensional array by a particular value?
You can try something like this
SELECT * FROM (
select c.id, c.name from courses c
union
select s.id, r.name,s.course_ID from sections s
union
select r.id, r.name,r.section_ID from resources r
)
You cant get multi dimensional result from mysql. The query for getting the elements should be like this:
select courses.id as coursesId,courses.name as coursesName,sections.id as sectionsId,sections.name as sectionsName,resources.id as resourcesId, resources.name as resourcesName
from courses
left join sections on courses.id=sections.course_id
left join resources on sections.id=resources.section_id;
But ofcourse it will not give you the array as you like.
if you are familiar with php then you can use this code i am writing only 2nd level you can write same way with third label
$final=array();
$c=-1;
$cid=false;
$cname=false;
$query = "SELECT c.*,s.*,r.* FROM courses AS c LEFT JOIN sections AS s ON c.id=s.course_id LEFT JOIN resources AS r ON r.section_id =s.id";
$result=mysql_query($query, $this->con) or die(mysql_error());
while($row= mysql_fetch_array($result)){
if($cid!=$row[2]){
$final['cources'][++$c]['id']=$cid=$row[0];
$final['cources'][$c]['name']=$cname=$row[1];
$s=-1;
}
$final['cources'][$c]['sections'][++$s]['id']=$row[2];
$final['cources'][$c]['sections'][$s]['course_id']=$row[3];
$final['cources'][$c]['sections'][$s]['name']=$row[4];
}
echo "<pre>";
print_r($final);
echo "</pre>";
//Outpur
Array
(
[cources] => Array
(
[0] => Array
(
[id] => 1
[name] => c1
[sections] => Array
(
[0] => Array
(
[id] => 1
[course_id] => 1
[name] => s1-1
)
[1] => Array
(
[id] => 1
[course_id] => 1
[name] => s1-1
)
)
)
[1] => Array
(
[id] => 2
[name] => c2
[sections] => Array
(
[0] => Array
(
[id] => 2
[course_id] => 2
[name] => s1-2
)
)
)
)
)
Sorry for the vague title, if anyone would like to edit it to reflect more about what I am posting, please do so. Here is the situation. I have 3 tables:
support:
id | contact_id | title | problem | etc
supportlogin:
id | contact_id | login | pass | etc
contact:
id | first_name | last_name | email | etc
I am loading the support bean just fine, and am accessing the contact info:
$support=R::load('support',1);
echo $support->contact->first_name;
I want to echo the supportlogin information similarly:
echo $support->contact->ownSupportlogin->login;
Is this possible, and am I doing it the right way? I have tried the following ways with no success:
echo $support->contact->supportlogin->login;
echo $support->contact->ownSupportlogin->login;
echo $support->contact->ownSupportlogin[0]->login;
EDIT: MORE INFO
I did print_r($support->contact) and was given the data:
RedBean_OODBBean Object
(
[null:RedBean_OODBBean:private] =>
[properties:RedBean_OODBBean:private] => Array
(
[id] => 109
[phone] => 1234580970
[first_name] => Tim
[last_name] => Withers
)
[__info:RedBean_OODBBean:private] => Array
(
[type] => contact
[sys.id] => id
[tainted] =>
)
[beanHelper:RedBean_OODBBean:private] => RedBean_BeanHelperFacade Object
(
)
[fetchType:RedBean_OODBBean:private] =>
)
And then I did print_r($support->contact->ownSupportlogin) and this showed up:
Array
(
[13] => RedBean_OODBBean Object
(
[null:RedBean_OODBBean:private] =>
[properties:RedBean_OODBBean:private] => Array
(
[id] => 13
[link] => fecd4ef67e8c789efa1792f9ee0efff4
[login] =>
[password] =>
[receiveemails] => 1
[contact_id] => 109
[role] => 1
)
[__info:RedBean_OODBBean:private] => Array
(
[type] => supportlogin
[sys.id] => id
[tainted] =>
)
[beanHelper:RedBean_OODBBean:private] => RedBean_BeanHelperFacade Object
(
)
[fetchType:RedBean_OODBBean:private] =>
)
)
I can access it using: echo $support->contact->ownSupportlogin[13]->login;, but doing it dynamically seems to be a problem....
Figured it out, and will leave it up in case anyone else has a similar problem:
This will only work if you have a 1:1 relationship. Redbean populates the ownSupportlogin as an array of all supportlogin rows related to the contact. If one table can have many child tables, then you will need to loop through that array and pull out the data you want. If it is a 1:1 relationship, then you can use PHP's reset() to access the data of the first element in the array:
echo reset($support->contact->ownSupporlogin)->login;