I have a table called facility.
Structure looks as follows:
id | name
---------
1 | Hotel
2 | Hospital
3 | medical shop
I have an other table which is taking data from the above table and keeping multiple values in one column. View looks like below:
id | facilities
---------------
1 | Hospital~~medical shop~~Hotel
2 | Hospital~~Hotel
3 | medical shop~~Hotel
If I want to join these two tables how does the query look like?
I tried this, but it didn't work:
select overview.facilities as facility
from overview join facility on facility.id=overview.facilities;
you can do this with a bit of hackery
select o.facilities as facility
from overview o
join facility f on find_in_set(f.facilities, replace(o.facilities, '~~', ','));
I would highly recommend you change the way you are storing data. currently it is considered un normalized and that quickly becomes a monster to deal with
you should change your table structure to look something more like this
+----------+--------------+
| facility |
+----------+--------------+
| id | name |
+----------+--------------+
| 1 | Hotel |
| 2 | Hospital |
| 3 | medical shop |
+----------+--------------+
+-----------+-------------+
| overview |
+-----------+-------------+
| id | facility_id |
+-----------+-------------+
| 1 | 2 |
| 2 | 3 |
| 3 | 1 |
| 4 | 2 |
| 5 | 1 |
| 6 | 3 |
| 7 | 1 |
+-----------+-------------+
Code Explanation:
basically you are wanting to find the matching facilities in the overview. one handy function MySQL has is FIND_IN_SET() that allows you to find an item in a comma separated string aka find_in_set(25, '11,23,25,26) would return true and that matching row would be returned... you are separating your facilities with the delimiter ~~ which wont work with find_in_set... so I used REPLACE() to change the ~~ to a comma and then used that in the JOIN condition. you can go from here in multiple ways.. for instance lets say you want the facility id's for the overview.. you just add in the select GROUP_CONCAT(f.id) and you have all of the id's... note if you do that you need to add a GROUP BY at the end of your query to tell it how you want the results grouped
Related
I have 2 tables. One with a list of clients and another with a list of data. I am trying to create a table in my view that lists the client name along with the sum of a column(job_total) in the data table. I am able to write a query that works fine in most situations. The problem is, if I have not yet created a record in the data table I need to still display the client name with a balance of zero on my table in my view. Need some direction on how to handle this. I was thinking I need to query my list of clients and loop through that query just not sure how to do it.
I want my view to look like below:
+-------------+---------+
| Client Name | Balance |
+-------------+---------+
| xxx | $75.00 |
| xxx | $100.00 |
| xxx | $0.00 |
+-------------+---------+
Here is a rough layout of the two tables in my database:
cj_clients
+----+-------------+
| id | client name |
+----+-------------+
| 1 | client1 |
| 2 | client2 |
| x | xxx |
+----+-------------+
cj_data
+----+-----------+-----------+
| id | client_id | job_total |
+----+-----------+-----------+
| 1 | 1 | 5.00 |
| 2 | 1 | 10.00 |
| 3 | 1 | 15.00 |
+----+-----------+-----------+
The below code returns the desired results except when no entries have yet been made to the cj_data table. Not sure how to still get the client in the table view with a balance of $0.
$this->db->select('client_name,client_id, sum(job_total) AS balance')
->from('cj_data')
->join('cj_clients','cj_data.client_id = cj_clients.id')
->group_by('client_name');
return $this->db->get()->result();
You need to give left join
$this->db->select('client_name,client_id, IFNULL(sum(job_total),0) AS balance')
->from('cj_data')
->join('cj_clients','cj_data.client_id = cj_clients.id',"left") // here
->group_by('client_name');
return $this->db->get()->result();
I wrote IFNULL condition if record not found or it will show all data for all clients in cj_clients
Note: the Default behaviour of CodeIgniter is it will add inner join
if join not specified
Hello :) I am fairly new to using INNER JOIN and still trying to comprehend it's logic which I think I am sort of beginning to understand. After being across a few different articles on the topic I have generated a query for finding duplicates in my table of phone numbers.
My table structure is as such:
+---------+-------+
| PhoneID | Phone |
+---------+-------+
Very simple. I created this query:
SELECT A.PhoneID, B.PhoneID FROM T_Phone A
INNER JOIN T_Phone B
ON A.Phone = B.Phone AND A.PhoneID < B.PhoneID
Which returns the ID of a phone that matches another one. I don't know how to word that properly so here is an example output:
+---------+---------+
| PhoneID | PhoneID |
+---------+---------+
| 17919 | 17969 |
| 17919 | 22206 |
| 17919 | 23837 |
| 17920 | 17970 |
| 17920 | 22203 |
| 17920 | 23834 |
| 17921 | 17971 |
| 17921 | 22225 |
| 17921 | 22465 |
| 17921 | 24011 |
| 17921 | 24047 |
| 17922 | 17972 |
| 17922 | 22198 |
| 17922 | 23879 |
| 17923 | 17973 |
| 17923 | 22199 |
| 17923 | 23880 |
+---------+---------+
You can note that on the left there is repeating IDs, the phone number that matches will be on the right (These are just the IDs of said numbers). what I am trying to accomplish, is to actually change a join table relative to the ID on the right. The join table structure is as such:
+----------+-----------+
| T_JoinID | T_PhoneID |
+----------+-----------+
Where T_JoinID is a larger object with a collection of those T_PhoneIDs, hence the join table. What I want to do is take a row from the original match query, and find the right side PhoneID in the join table, then update that item in the Join to be equal to the left side PhoneID. Repeating this for each row.
It's sort of a way to save space and get rid of matching numbers, I can just point the matching ones to the original and use that as a reference when I need to retrieve it.
After that I need to actually delete the original numbers that I reset the reference for but... This seems like a job for 2 or 3 different queries.
EDIT:
Sorry I know I didn't include enough detail. Here is some additional info:
My exact table structure is not the same as here but I am only using the columns that I listed so I didn't consider the fact that any of the others would matter. Most of the tables have a unique ID that is auto incremented. The phone table has carrier, type, ect columns. The additional columns I felt were irrelevant to include, but if there is a solution that includes the auto incremented ID of each table, let me know :) Anyway, I sort of found a solution, using multiple queries though I am still interested to learn and apply knowledge based on this question. So I have a that join table that I mentioned. It might look something like this for the expected results. There is a before and after table in one sorry for poor formatting.
+--------------------+---------+----------+---------+
| Join Table Results | | | |
+--------------------+---------+----------+---------+
| Before | | After | |
| Join | Table | Join | Table |
| PersonID | PhoneID | PersonID | PhoneID |
| 1 | 1 | 1 | 1 |
| 1 | 2 | 1 | 2 |
| 1 | 3 | 1 | 3 |
| 2 | 4 | 2 | 1 |
| 2 | 5 | 2 | 5 |
| 2 | 6 | 2 | 6 |
| 3 | 7 | 3 | 5 |
| 3 | 8 | 3 | 5 |
| 3 | 9 | 3 | 5 |
| 3 | 10 | 3 | 8 |
| 3 | 11 | 3 | 9 |
+--------------------+---------+----------+---------+
So you can see that in the before columns, 7, 8, and 9 would all be duplicate phone numbers in the PhoneID - PhoneID relationship table I posted originally. After the query I wanted to retrieve the duplicates using the PhoneID - PhoneID comparison and take the ones that match, to change the join table in a way that I have shown directly above. So 7, 8, 9 all turn to 5. Because 5 is the original number, and 7, 8, 9 coincidentally were duplicates of 5. So I am basically pointing all of them to 5, and then deleting what would have been 7, 8, 9 in my Phone table since they all have a new relationship to 5. Is this making sense? xD It sounds outrageous typing it out.
End Edit
How can I improve my query to accomplish this task? Is it possible using an UPDATE statement? I was also considering just looping through this output and updating each row individually but I had a hope to just use a single query to save time and code. Typing it out makes me feel a tad obnoxious but I had hope there was a solution out there!
Thank you to anyone in advance for taking your time to help me out :) I really appreciate it. If it sounds outlandish, let me know I will just use multiple queries.
i am trying to build something like an order management tool for a car garage.
The main function of the tool is to manage repair orders and inspection orders as well
Therefore i have created this following three tables.
In the first one you can see the cars and the state of the repair and inspection.
The second one shows the information about the single repair orders the relation between the first and this is 1:n.
The last one shows the automaticly created inspection orders for each car out of the first table. This is an 1:n relation as well.
So what i try to do is to show all the open repair and inspection orders for the cars in one table. But only the open ones.
I tried it with some where statements but i got totaly confused.
My question is, how i can realise it?
+------+--------------------------+----------+------------+
| IDWZ | wz_name | wz_stand | wz_vistand |
+------+--------------------------+----------+------------+
| 1 | Querbr?cke vorn | 0 | 0 |
| 2 | Front Lateral Support | 0 | 1 |
| 3 | Rear Support | 1 | 1 |
| 4 | MID-X-Member Upper Shell | 1 | 1 |
| 5 | Front Lateral Support | 1 | 1 |
+------+--------------------------+----------+------------+
+---------+-----------------+--------------+
| IDWZTBL | rep_wzrepstatus | rep_wzfehler |
+---------+-----------------+--------------+
| 2 | 1 | REP 1 |
| 1 | 1 | REp2 |
| 1 | 1 | REp 3 MASS |
| 1 | 0 | 444 |
| 2 | 0 | |
+---------+-----------------+--------------+
+--------+-------------+
| VIWZID | vi_repstand |
+--------+-------------+
| 1 | 0 |
+--------+-------------+
Sry for that!
So the IDWZ is the foreign KEY in the second table(IDWZTBL) and in the third (VIWZID).
I tried it with
SELECT wz_name, wz_stand, wz_vistand, rep_wzrepstatus, vi_repstand FROM tbl_wz LEFT JOIN tbl_orders ON tbl_wz.IDWZ = tbl_orders.IDWZTBL LEFT JOIN tbl_vi ON tbl_wz.IDWZ = tbl_vi.VIWZID WHERE wz_stand='0' AND rep_wzrepstatus='0' ...
Only for the first table cars to the second one repair orders, that WHERE staement (WHERE wz_stand='0' AND rep_wzrepstatus='0') works fine.
But if i try to add the third table (VI) doing the same, i could fetch the result i wanna have.
What i wanna see in the Overview table is only the last open repair order and the last open inspection order.
I am trying to get a list of distinct values from the columns out of a table.
Each column can contain multiple comma delimited values. I just want to eliminate duplicate values and come up with a list of unique values.
I know how to do this with PHP by grabbing the entire table and then looping the rows and placing the unique values into a unique array.
But can the same thing be done with a MySQL query?
My table looks something like this:
| ID | VALUES |
---------------------------------------------------
| 1 | Acadian,Dart,Monarch |
| 2 | Cadillac,Dart,Lincoln,Uplander |
| 3 | Acadian,Freestar,Saturn |
| 4 | Cadillac,Uplander |
| 5 | Dart |
| 6 | Dart,Cadillac,Freestar,Lincoln,Uplander |
So my list of unique VALUES would then contain:
Acadian
Cadillac
Dart
Freestar
Lincoln
Monarch
Saturn
Uplander
Can this be done with a MySQL call alone, or is there a need for some PHP sorting as well?
Thanks
Why would you store your data like this in a database? You deliberately nullify all the extensive querying features you would want to use a database for in the first place. Instead, have a table like this:
| valueID | groupID | name |
----------------------------------
| 1 | 1 | Acadian |
| 2 | 1 | Dart |
| 3 | 1 | Monarch |
| 4 | 2 | Cadillac |
| 2 | 2 | Dart |
Notice the different valueID for Dart compared to Matthew's suggestion. That's to have same values have the same valueID (you may want to refer to these later on, and you don't want to make the same mistake of not thinking ahead again, do you?). Then make the primary key contain both the valueID and the groupID.
Then, to answer your actual question, you can retrieve all distinct values through this query:
SELECT name FROM mytable GROUP BY valueID
(GROUP BY should perform better here than a DISTINCT since it shouldn't have to do a table scan)
I would suggest selecting (and splitting) into a temp table and then making a call against that.
First, there is apparently no split function in MySQL http://blog.fedecarg.com/2009/02/22/mysql-split-string-function/ (this is three years old so someone can comment if this has changed?)
Push all of it into a temp table and select from there.
Better would be if it is possible to break these out into a table with this structure:
| ID | VALUES |AttachedRecordID |
---------------------------------------------------------------------
| 1 | Acadian | 1 |
| 2 | Dart | 1 |
| 3 | Monarch | 1 |
| 4 | Cadillac | 2 |
| 5 | Dart | 2 |
etc.
i have a table in following format:
id | title
---+----------------------------
1 | php jobs, usa
3 | usa, php, jobs
4 | ca, mysql developer
5 | developer
i want to get the most popular keywords in title field, please guide.
If you have a list of keywords, you can do the following:
select kw.keyword, count(*)
from t cross join
keywords kw
on concat(', ', t.title, ',') like concat(', ', kw.keyword, ',')
As others have mentioned, though, you have a non-relational database design. The keywords in the title should be stored in separate rows, rather than as a comma separated list.
If your data is small (a few hundred thousand rows or less), you can put it into Excel, use the text-to-columns function, rearrange the keywords, and create a new, better table in the database.
SELECT title 1, COUNT(*) FROM table GROUP BY title 1
EDIT
Since you've edited and presented a non-normalized table, I would recommend you normalize it.
Have a read of: http://blog.fedecarg.com/2009/02/22/mysql-split-string-function/
You need to modify your database. You should have something like this:
items
+----+---------------+
| id | title |
+----+---------------+
| 1 | something |
| 3 | another thing |
| 4 | yet another |
| 5 | one last one |
+----+---------------+
keywords
+----+-----------------+
| id | keyword |
+----+-----------------+
| 1 | php jobs |
| 2 | usa |
| 3 | php |
| 4 | jobs |
| 5 | ca |
| 6 | mysql developer |
| 7 | developer |
+----+-----------------+
items_to_keywords
+---------+------------+
| item_id | keyword_id |
+---------+------------+
| 1 | 1 |
| 1 | 2 |
| 3 | 2 |
| 3 | 3 |
| 3 | 4 |
| 4 | 5 |
| 4 | 6 |
| 5 | 7 |
+---------+------------+
Do you see the advantage? The ability to make relations is what you should be leveraging here.