I was able to join 3 tables and count the data set, bet getting the columns on specific table it only see the 3rd table column..
SELECT *
FROM `InvoiceItemTable` a
JOIN `InvoiceTable` b
ON (b.id = a.invoice)
JOIN `products` c
ON (a.product = c.id)
WHERE b.status='1' AND c.store = '2'
//$invoices = $inginger->fetch(PDO::FETCH_ASSOC))
echo $invoices['a.price'];
This price return error : Undefined index: a.price in...
there is "price" in the first table(InvoiceItemTable).
echo $invoices['invoice'];
There is invoice in first table(InvoiceItemTable) and it returns it works
I dont want to use $invoices['price'] because there is 'price' colum in the third table too and that is what it returns, I want to get the price in the first table. $invoices['price.InvoiceItemTable'] returns undefined index
php wont recognize $invoices['a.price']; you have to use $invoices['price'];
if you have same fieldname in multiple tables you have to create an alias
SELECT a.price as a_price, b.price as b_price, c.price as c_price
and then you can use $invoices['a_price']
In general, it's much better to explicitly define your columns. In doing so you can add a specific name to the the column you're interested in (or conversely change the name of the one you're not to remove ambiguity)
For examples sake, I'm just showing the columns you've described but it would look something like.
SELECT a.price as price, c.price as product_price
FROM `InvoiceItemTable` a
JOIN `InvoiceTable` b ON (b.id = a.invoice)
JOIN `products` c ON (a.product = c.id)
WHERE b.status='1' AND c.store = '2';
Doing naming such as this is more work, but insulates your code from changes and more explicitly shows the reader what is being returned.
Related
I am trying to make a "recipe" system inside a game. The player can own a company and craft items in there.
I currently fetch the recipes per company type but I don't know how to write the query in a way that I can also fetch the item names and images if the item_id is not empty.
This is working:
SELECT a.recipe_id,
a.item1_id,
a.item1_uses,
a.item2_id,
a.item2_uses,
a.item3_id,
a.item3_uses,
a.item4_id,
a.item4_uses,
a.item5_id,
a.item5_uses,
a.newitem_id,
a.newitem_uses,
a.craft_description,
a.craft_button
FROM
company_recipes AS a,
company_types AS b
WHERE
a.type_id = b.type_id
AND
b.type_id = '".$type."';
"
A recipe can contain for example two items needed to craft something new, but it could also be 5. So if it's only 2, I only want to fetch the img, name of these 2 and the rest can be skipped.
I have a different table store_items that contains the img and name of the item. I was thinking something along the lines of an IF ELSE or CASE WHEN inside the query, but I'm not sure how I'd do that.
Something like: SELECT c.img, c.name FROM store_items AS c IF a.item1_id is not NULL.
I feel like I'm close to the solution, but missing the last step.
Thanks for the tips #jarlh, I've changed the code and came to this result. If you have any more tips to do it better I'm happy to listen. (I'm still a junior and thought myself by trial and error, so I might not have the best solutions at times... Which is why tips are highly appreciated).
SELECT cr.recipe_id,
cr.item1_id,
cr.item1_uses,
si1.name,
si1.img,
cr.item2_id,
cr.item2_uses,
si2.name,
si2.img,
cr.item3_id,
cr.item3_uses,
si3.name,
si3.img,
cr.item4_id,
cr.item4_uses,
si4.name,
si4.img,
cr.item5_id,
cr.item5_uses,
si5.name,
si5.img,
cr.newitem_id,
cr.newitem_uses,
si_new.name,
si_new.img,
cr.craft_description,
cr.craft_button
FROM
company_recipes AS cr
INNER JOIN company_types AS ct ON cr.type_id = ct.type_id
LEFT JOIN store_items AS si1 ON cr.item1_id = si1.item_id
LEFT JOIN store_items AS si2 ON cr.item2_id = si2.item_id
LEFT JOIN store_items AS si3 ON cr.item3_id = si3.item_id
LEFT JOIN store_items AS si4 ON cr.item4_id = si4.item_id
LEFT JOIN store_items AS si5 ON cr.item5_id = si5.item_id
LEFT JOIN store_items AS si_new ON cr.newitem_id = si_new.item_id
WHERE
ct.type_id = '".$type."';
I'm basically fetching everything now and handle the NULLs in the php code now.
Without seeing more info its had to see what you are trying achieve but you could start by using the the users inpute of the game to determine what data is first required before futher filtering. Try this:
Declare #Value int
set #Value = #User_input --- uses what ever the game user will
SELECT
a.recipe_id,
a.item1_id,
a.item1_uses,
a.item2_id,
a.item2_uses,
a.item3_id,
a.item3_uses,
a.item4_id,
a.item4_uses,
a.item5_id,
a.item5_uses,
a.newitem_id,
a.newitem_uses,
a.craft_description,
a.craft_button
--- you can insert more columns but i stopped here as i dont know what data you have in the other tables.
FROM
company_recipes a
INNER JOIN company_types b ON a.type_id = b.type_id
INNER JOIN store_items c ON c.type_id = b.type_id
WHERE
b.type_id = #Value; --- '".$type."';
$query='SELECT * FROM #__virtuemart_products as a
LEFT JOIN #__virtuemart_products_en_gb as b ON a.virtuemart_product_id = b.virtuemart_product_id
INNER JOIN #__virtuemart_product_categories as c ON a.virtuemart_product_id=c.virtuemart_product_id
INNER JOIN #__virtuemart_categories_en_gb as d ON c.virtuemart_category_id = d.virtuemart_category_id
WHERE b.slug LIKE "'.$current.'%" AND a.product_parent_id = 0
AND d.category_name="'.$query_title.'"' ;
$db->setQuery($query);
$options=$db->loadObjectList();
This is the query i use to parse some products from my db. The problem is:
Table: virtuemart_products_en_gb has a collumn named slug
Table: virtuemart_categories_en_gb has also a collumn named slug
When i used $row->slug it parsed the virtuemart_categories_en_gb slug.
So after i var_dumped the ObjectList i see that there is only 1 collumn named slug. After i used the same query in phpmyadmin, it returns me 2 collumns named slug.
I think i could fix that selecting every single record individual and setting first slug as slug1 and second as slug2.
For example: SELECT id,username,password,b.slug as slug1,c.slug as slug2 etc
Is there any better way ? Cause i need to parse really many fields and that would make the query really huge.And why the php query returns only 1 field named slug while phpmyadmin returns both of em ?
Thanks in advance.
You can specify * after selecting the columns with the same name. For example,
SELECT *, b.slug as slug1,c.slug as slug2
FROM #__virtuemart_products as a
LEFT JOIN #__virtuemart_products_en_gb as b ON a.virtuemart_product_id = b.virtuemart_product_id
INNER JOIN #__virtuemart_product_categories as c ON a.virtuemart_product_id=c.virtuemart_product_id
INNER JOIN #__virtuemart_categories_en_gb as d ON c.virtuemart_category_id = d.virtuemart_category_id
WHERE b.slug LIKE "'.$current.'%" AND a.product_parent_id = 0
AND d.category_name="'.$query_title.'"
I have two tables and joined them to one different table
1 table named 'rec_dept'
id_dept
id_divisi
nama_dept
2 table named 'rec_divisi'
id_divisi
nama_div
3 joined table named 'rec_divdep'
id_divdep
id_divisi
id_dept
How to get nama_dept where in the same id_divisi?
Maybe you're looking for this:
SELECT `nama_dept` FROM `rec_dept` WHERE `id_divisi` IN (SELECT `id_divisi` FROM `rec_divdep`);
Hope that helps
you can do a SELECT query with a LEFT JOIN function to get data
SELECT a.`nama_dept` FROM `rec_dept` a
LEFT JOIN `rec_divisi` b
ON a.`id_divisi` = b.`id_divisi`
ORDER BY a.`id_divisi` ASC
SELECT documentation
LEFT JOIN documentation
select a.id_dept, a.id_divisi, a.nama_dept, b.id_divisi, b.nama_div, c.id_divdep, c.id_divisi from rec_divdep as c left join rec_divisi as b on (c.id_divisi = b.id_divisi) left join rec_dept as a on (c.id_divisi = a.id_divisi)
what database do you use. I code mine as mysql, basically I condition the three tables that has same id_divisi. I did not test it but I am pretty sure of the logic based on what I understand.
I have an instrument list and teachers instrument list.
I would like to get a full instrument list with id and name.
Then check the teachers_instrument table for their instruments and if a specific teacher has the instrument add NULL or 1 value in a new column.
I can then take this to loop over some instrument checkboxes in Codeigniter, it just seems to make more sense to pull the data as I need it from the DB but am struggling to write the query.
teaching_instrument_list
- id
- instrument_name
teachers_instruments
- id
- teacher_id
- teacher_instrument_id
SELECT
a.instrument,
a.id
FROM
teaching_instrument_list a
LEFT JOIN
(
SELECT teachers_instruments.teacher_instrument_id
FROM teachers_instruments
WHERE teacher_id = 170
) b ON a.id = b.teacher_instrument_id
my query would look like this:
instrument name id value
--------------- -- -----
woodwinds 1 if the teacher has this instrument, set 1
brass 2 0
strings 3 1
One possible approach:
SELECT i.instrument_name, COUNT(ti.teacher_id) AS used_by
FROM teaching_instrument_list AS i
LEFT JOIN teachers_instruments AS ti
ON ti.teacher_instrument_id = i.id
GROUP BY ti.teacher_instrument_id
ORDER BY i.id;
Here's SQL Fiddle (tables' naming is a bit different).
Explanation: with LEFT JOIN on instrument_id we'll get as many teacher_id values for each instrument as teachers using it are - or just a single NULL value, if none uses it. The next step is to use GROUP BY and COUNT() to, well, group the result set by instruments and count their users (excluding NULL-valued rows).
If what you want is to show all the instruments and some flag showing whether or now a teacher uses it, you need another LEFT JOIN:
SELECT i.instrument_name, NOT ISNULL(teacher_id) AS in_use
FROM teaching_instrument_list AS i
LEFT JOIN teachers_instruments AS ti
ON ti.teacher_instrument_id = i.id
AND ti.teacher_id = :teacher_id;
Demo.
Well this can be achieved like this
SELECT
id,
instrument_name,
if(ti.teacher_instrument_id IS NULL,0,1) as `Value`
from teaching_instrument_list as til
LEFT JOIN teachers_instruments as ti
on ti.teacher_instrument_id = til.id
Add a column and check for teacher_instrument_id. If found set Value to 1 else 0.
I've been working on a project that until now has only needed to find 1 row from the joined table. But now I need to grab multiple rows..
So as it stand my sql works something like:
Select rows for each company for this particular project which alone would find company details (name, id, telephone.. blah).
Then I join a table that contains form data submitted for each company (multiple forms - so multiple records)
Until now i have been specifying one formid to look for in the join, but now i need to specify multiple ones.
If I use WHERE form_id = 1 OR form_id = 2 OR form_id = 3 ... I get a result of only the first form match that is found per company..
If I mix up the query so it looks for the forms 1st and returns multiple records for each company with different form data - that works in this sense..
But I am then looping through this array in a view and creating a table row per record (previously each row was a new company) but using the latter would cause multiple records to show for the same company.
Any way I can do this? I tried group by with the latter method but this results in only 1 record again.
SELECT DISTINCT p.project_company_has_user_id, p.project_company_has_user_project_id, p.project_company_has_user_user_id, c.company_id, c.company_hall_no, c.company_company_name, c.company_type, c.company_country, c.company_stand_number, c.company_image_file_1, p2.project_id, p2.project_name, u.user_id, u.user_username, o.orders_id, o2.order_detail_id, o2.order_detail_product_id, f2.form_question_has_answer_id, f2.form_question_has_answer_request, f2.form_question_has_answer_form_id, f2.form_question_has_answer_user_id
FROM project_company_has_user p
INNER JOIN company c ON p.project_company_has_user_company_id = c.company_id
INNER JOIN project p2 ON p.project_company_has_user_project_id = p2.project_id
INNER JOIN user u ON p.project_company_has_user_user_id = u.user_id
INNER JOIN form f ON p.project_company_has_user_project_id = f.form_project_id
LEFT JOIN orders o ON p.project_company_has_user_user_id = o.orders_user_id
LEFT JOIN order_detail o2 ON ((o2.order_detail_orders_id = o.orders_id AND (o2.order_detail_product_id = 65 OR o2.order_detail_product_id = 68 OR o2.order_detail_product_id = 64)))
LEFT JOIN form_question_has_answer f2 ON ((f2.form_question_has_answer_form_id = 297 AND f2.form_question_has_answer_user_id = p.project_company_has_user_user_id))
WHERE (f.form_template_name = "custom" AND p.project_company_has_user_garbage_collection = 0 AND p.project_company_has_user_project_id = 48) AND (LCASE(c.company_country) LIKE "%uk%" OR LCASE(c.company_country) LIKE "%uk%") ORDER BY company_company_name asc
you need another field in order_detail as o2 . this field is row_index(position),etc for positioning record
LEFT JOIN order_detail o2 ON (o2.row_index=1 AND (o2.order_detail_orders_id = o.orders_id AND (o2.order_detail_product_id = 65 OR o2.order_detail_product_id = 68 OR o2.order_detail_product_id = 64)))
Personally I would use an Outer Join for the table of which elements you need to list all matches. Should you them need to clean up that data you can build the logic into the Join Condition (as step 2). Depending on the volume of data you are handling and whether or not you need to reuse it later in the same proc, you may want to post that primary dataset into a temp table and use that as source (primary) for your later logic.
Hope that helps. If you need the code, let me know, but it is pretty straight forward.
Regards
Mac