I'm creating a database for compressed files with some media files. To connect the files within every .zip, i'me using a middle table compressed_has_medium.
The Database
medium compressed_has_medium compressed
id | filename id | medium_id | compressed_id id | filename
-------------- ------------------------------ -------------
1 | file1.mp3 1 | 1 | 1 1 | compressed1.zip
2 | file2.mp3 1 | 2 | 1 2 | compressed2.zip
3 | file3.mp3 1 | 3 | 1 3 | compressed3.zip
4 | file4.mp3 1 | 4 | 1
5 | file5.mp3 1 | 5 | 1
6 | file6.mp3 1 | 6 | 1
7 | file7.mp3 1 | 1 | 2
8 | file8.mp3 1 | 2 | 2
9 | file9.mp3 1 | 3 | 2
The Problem
I need to return every .zip that contain the ID's that I send to MySQL.
If the zip1 has the files 1,2,3,4,5,6 and I want the zip for the files 3,4, it should return me the zip1.
But if the zip2 has the files 1,2,3 and I request the files 3,4, it shouldn't be returned.
The partial solution
I've tried a lot and get to this solution: http://sqlfiddle.com/#!9/cb0864/37 but It's a really ugly query and probably not efficient.
SELECT c.*, GROUP_CONCAT(cm.medium_id) as media
FROM compressed as c
INNER JOIN compressed_has_medium as cm
ON cm.compressed_id = c.id
GROUP BY cm.compressed_id
HAVING (media LIKE '%,3,%' OR media LIKE '3,%' OR media LIKE '%3')
AND (media LIKE '%,4,%' OR media LIKE '4,%' OR media LIKE '%,4')
Do you know a better way to do it?
Many tanks!
May be this is what you expecting i believe
i have changed the query in your fiddle : http://sqlfiddle.com/#!9/cb0864/62
SELECT c.*,GROUP_CONCAT(cm.medium_id) as media
FROM compressed as c
LEFT JOIN compressed_has_medium as cm
ON cm.compressed_id = c.id
WHERE cm.medium_id in (3,4)
GROUP BY cm.compressed_id
having sum(cm.medium_id in (3,4)) = 2 and // 2 represents the numbers of medium id you are entering
sum(cm.medium_id not in (3,4)) = 0
Related
I have two MySQL tables that follow this format:
mod_site_content mod_site_tmplvar_contentvalues
----------------------------- ---------------------------------------------
id | pagetitle | content id | tmplvarid | contentid | value
----------------------------- ---------------------------------------------
1 | Project 1 | <p> ... </p> 1 | 1 | 1 | 12.08.2014
2 | Project 2 | <p> ... </p> 2 | 1 | 2 | 13.08.2014
3 | Project 3 | <p> ... </p> 3 | 2 | 1 | <img src="..."/>
4 | Project 4 | <p> ... </p> 4 | 2 | 4 | <img src="..."/>
5 | Project 5 | <p> ... </p> 5 | 3 | 4 | [{"key":"val"...
6 | Project 6 | <p> ... </p> 6 | 3 | 5 | [{"key":"val"...
mod_site_content is a list of resources that represent webpages, and mod_site_tmplvar_contentvalues are (optional) additional page content.
Let's say I want to find a string in mod_site_content.pagetitle or mod_site_content.content, but if not present, also search mod_site_tmplvar_contentvalues.value but only where tmplvarid is 2 or 3.
Currently, the closest I've got is with the following query:
SELECT * FROM mod_site_content
INNER JOIN mod_site_tmplvar_contentvalues
ON mod_site_content.id = mod_site_tmplvar_contentvalues.contentid
WHERE
tmplvarid = 2 OR
tmplvarid = 3 AND
pagetitle LIKE ? OR
content LIKE ? OR
value LIKE ?
But this generates a larger array of results than expected, with what appear to be a number of duplicates.
It also merges the two tables in an unexpected manner; e.g. if Project 1 doesn't contain a match, but id 3 in the second table does, I'd like to return Project 1 with the result from the second table pushed into the array.
I know this question is a little verbose, but I'm attempting to be a clear as possible, knowing that my SQL knowledge is quite limited.
Can you try running the below code:
SELECT * FROM mod_site_content
INNER JOIN mod_site_tmplvar_contentvalues
ON mod_site_content.id = mod_site_tmplvar_contentvalues.contentid
WHERE tmplvarid IN (2,3) AND
1= (CASE WHEN pagetitle LIKE ? OR content LIKE ? THEN 1
WHEN value LIKE ? THEN 1
ELSE 0 END)
Some background: an 'image' is part of one 'photoshoot', and may be a part of zero or many 'galleries'. My tables:
'shoots' table:
+----+--------------+
| id | name |
+----+--------------+
| 1 | Test shoot |
| 2 | Another test |
| 3 | Final test |
+----+--------------+
'images' table:
+----+-------------------+------------------+
| id | original_filename | storage_location |
+----+-------------------+------------------+
| 1 | test.jpg | store/test.jpg |
| 2 | test.jpg | store/test.jpg |
| 3 | test.jpg | store/test.jpg |
+----+-------------------+------------------+
'shoot_images' table:
+----------+----------+
| shoot_id | image_id |
+----------+----------+
| 1 | 1 |
| 1 | 2 |
| 3 | 3 |
+----------+----------+
'gallery_images' table:
+------------+----------+
| gallery_id | image_id |
+------------+----------+
| 1 | 1 |
| 1 | 2 |
| 2 | 3 |
| 3 | 1 |
| 4 | 1 |
+------------+----------+
What I'd like to get back, so I can say 'For this photoshoot, there are X images in total, and these images are featured in Y galleries:
+----+--------------+-------------+---------------+
| id | name | image_count | gallery_count |
+----+--------------+-------------+---------------+
| 3 | Final test | 1 | 1 |
| 2 | Another test | 0 | 0 |
| 1 | Test shoot | 2 | 4 |
+----+--------------+-------------+---------------+
I'm currently trying the SQL below, which appears to work correctly but only ever returns one row. I can't work out why this is happening. Curiously, the below also returns a row even when 'shoots' is empty.
SELECT shoots.id,
shoots.name,
COUNT(DISTINCT shoot_images.image_id) AS image_count,
COUNT(DISTINCT gallery_images.gallery_id) AS gallery_count
FROM shoots
LEFT JOIN shoot_images ON shoots.id=shoot_images.shoot_id
LEFT JOIN gallery_images ON shoot_images.image_id=gallery_images.image_id
ORDER BY shoots.id DESC
Thanks for taking the time to look at this :)
You are missing the GROUP BY clause:
SELECT
shoots.id,
shoots.name,
COUNT(DISTINCT shoot_images.image_id) AS image_count,
COUNT(DISTINCT gallery_images.gallery_id) AS gallery_count
FROM shoots
LEFT JOIN shoot_images ON shoots.id=shoot_images.shoot_id
LEFT JOIN gallery_images ON shoot_images.image_id=gallery_images.image_id
GROUP BY 1, 2 -- Added this line
ORDER BY shoots.id DESC
Note: The SQL standard allows GROUP BY to be given either column names or column numbers, so GROUP BY 1, 2 is equivalent to GROUP BY shoots.id, shoots.name in this case. There are many who consider this "bad coding practice" and advocate always using the column names, but I find it makes the code a lot more readable and maintainable and I've been writing SQL since before many users on this site were born, and it's never cause me a problem using this syntax.
FYI, the reason you were getting one row before, and not getting and error, is that in mysql, unlike any other database I know, you are allowed to omit the group by clause when using aggregating functions. In such cases, instead of throwing a syntax exception, mysql returns the first row for each unique combination of non-aggregate columns.
Although at first this may seem abhorrent to SQL purists, it can be incredibly handy!
You should look into the MySQL function group by.
I am trying to do multiple joins on the same MySQL table, but am not getting the results that I expect to get. Hopefully someone can point out my mistake(s).
Table 1 - cpe Table
|id | name
|----------
| 1 | cat
| 2 | dog
| 3 | mouse
| 4 | snake
-----------
Table 2 - AutoSelect
|id | name | cpe1_id | cpe2_id | cpe3_id |
|-----------------------------------------------
| 1 | user1 | 1 | 3 | 4 |
| 2 | user2 | 3 | 1 | 2 |
| 3 | user3 | 3 | 3 | 2 |
| 4 | user4 | 4 | 2 | 1 |
------------------------------------------------
I would like to see an output of
user1 | cat | mouse | snake |
user2 | mouse | snake | dog |
..etc
Here is what I have tried
SELECT * FROM AutoSelect
LEFT JOIN cpe ON
( cpe.id = AutoSelect.cpe1_id ) AND
( cpe.id = AutoSelect.cpe2_id ) AND
( cpe.id = AutoSelect.cpe3_id )
I get blank results. I thought i knew how to do these joins, but apparently when I'm trying to match cpe?_id with the name of the cpe table.
Thanks in advance for any assistance.
You need left join 3 times as well. Currently your query only joins 1 time with 3 critieria as to the join. This should do:
SELECT a.name, cpe1.name, cpe2.name, cpe3.name FROM AutoSelect as a
LEFT JOIN cpe as cpe1 ON ( cpe1.id = a.cpe1_id )
LEFT JOIN cpe as cpe2 ON ( cpe2.id = a.cpe2_id )
LEFT JOIN cpe as cpe3 ON ( cpe3.id = a.cpe3_id )
And you probably mean to INNER JOIN rather than LEFT JOIN unless NULL values are allowed in your AutoSelect table.
I think your design is wrong.
With tables like that, you get it the way it's meant to be in relational databases :
table 1 : animal
id name
1 cat
2 dog
3 mouse
4 snake
table 2 : user
|id | name |
|--------------
| 1 | user1 |
| 2 | user2 |
| 3 | user3 |
| 4 | user4 |
table 3 : association
|id_user | id_animal|
|--------------------
| 1 | 1 |
| 1 | 3 |
| 1 | 4 |
| 2 | 3 |
| 2 | 1 |
| 2 | 2 |
| 3 | 3 |
| 3 | 2
| 4 | 4 |
| 4 | 2 |
| 4 | 1 |
---------------------
Then :
select u.name, a.name from user u, animal a, association ass where ass.user_id = u.id and ass.animal_id = a.id;
In this case, your solution won't produce a good dynamic database. There are other ways to make combinations of multiple tables. I can show you by my own database what you should use and when you should use this solution. The scheme is in dutch, but you'll probably understand the keywords.
Like you, I had to combine my windmills with a kWh-meter, which has to measure the energyproduction of my windmills. What you should do, is this case, is making another table(in my case molenkWhlink). Make sure your tables are INNODB-types(for making Foreign keys). What I've done is combining my meters and mills by putting a pointer(a foreign key) of their ID(in Dutch Volgnummer) in the new table. An advantage you may not need, but I certainly did, is the fact I was able to extend the extra table with connection and disconnection info like Timestamps and metervalues when linking or unlinking. This makes your database way more dynamic.
In my case, I Also had a table for meassurements(metingoverzicht). As you can see in the scheme, I've got 2 lines going from Metingoverzicht to molenkwhlink. The reason for this is quite simple. All meassurements I take, will be saved in table Metingoverzicht. Daily meassurements(which are scheduled) will have a special boolean put on, but unscheduled meassurements, will also me saved here, with the bollean turned off. When switching meters, I need the endvalue from the leaving meter and the startvalue from the new meter, to calculate the value of todays eneryproduction. This is where your solution comes in and an extra table won't work. Usually, when you need just one value from another table a JOIN will be used. The problem in this case is, I've got 2 meassurementIDs in 1 link(1 for connecting and 1 for disconnecting). They both point to the same tablecolumn, because they both need to hold the same type of information. That is when you can use a double JOIN from one table towards the other. Because, both values will only be used once, and just needed to be saved in a different place to avoid having 1 action stored on different locations, which should always be avoided.
http://s1101.photobucket.com/user/Manuel_Barcelona/media/schemedatabase.jpg.html
I've checked out a few of the stackoverflow questions and there are similar questions, but didn't quite put my fingers on this one.
If you have a table like this:
uid cat_uid itm_uid
1 1 4
2 1 5
3 2 6
4 2 7
5 3 8
6 3 9
where the uid column in auto_incremented and the cat_uid references a
category of relevance to filter on and the itm_uid values are the one
we're seeking
I would like to get a result set that contains the following sample results:
array (
0 => array (1 => array(4,5)),
1 => array (2 => array(6,7)),
2 => array (3 => array(8,9))
)
An example issue is - select 2 records from each category (however many categories there may be) and make sure they are the last 2 entries by uid in those categories.
I'm not sure how to structure the question to allow an answer, and any hints on a method for the solution would be welcome!
EDIT:
This wasn't a very clear question, so let me extend the scenario to something more tangible.
I have a set of records being entered into categories and I would like to select, with as few queries as possible, the latest 2 records entered per category, so that when I list out the contents of those categories, I will have at least 2 records per category (assuming that there are 2 or more already in the database). A similar query was in place that selected the last 100 records and filtered them into categories, but for small numbers of categories with some being updated faster than others can lead to having the top 100 not consisting of members from every category, so to try to resolve that, I was looking for a way to select 2 records from each category (or N-records assuming it's the same per-category) and for those 2 records to be the last entered. A date field is available to sort on, but the itm_uid itself could be used to indicate inserted order.
SELECT cat_uid, itm_uid,
IF( #cat = cat_uid, #cat_row := #cat_row + 1, #cat_row := 0 ) AS cat_row,
#cat := cat_uid
FROM my_table
JOIN (SELECT #cat_row := 0, #cat := 0) AS init
HAVING cat_row < 2
ORDER BY cat_uid, uid DESC
You will have two extra columns in the results, just ignore them.
This is the logic:
We sort the table by cat_uid, uid descending, then we start from the top and give each row a "row number" (cat_row) we reset this row number to zero whenever cat_uid changes:
---------------------------------------
| uid | cat_uid | itm_uid | cat_row |
| 45 | 4 | 34 | 0 |
| 33 | 4 | 54 | 1 |
| 31 | 4 | 12 | 2 |
| 12 | 4 | 51 | 3 |
| 56 | 6 | 11 | 0 |
| 20 | 6 | 64 | 1 |
| 16 | 6 | 76 | 2 |
| ... | ... | ... | ... |
---------------------------------------
now if we keep only the rows that have cat_row < 2 we get the results we want:
---------------------------------------
| uid | cat_uid | itm_uid | cat_row |
| 45 | 4 | 34 | 0 |
| 33 | 4 | 54 | 1 |
| 56 | 6 | 11 | 0 |
| 20 | 6 | 64 | 1 |
| ... | ... | ... | ... |
---------------------------------------
This is called an adjacent tree model or a parent-child tree model. It's one of the simplier tree model where there is only 1 pointer or 1 leaf. You would solve your query with a recursion or using a Self Join. Sadly MySQL doesn't support recursive queries, maybe it's working with prepared statements. I want to suggest you an Self Join. With a Self Join you can get all the rows from the right side and the left side with a special condition.
select t1.cat_uid, t2.cat_uid, t1.itm_uid, t2.itm_uid From t1 Inner Join t2 On t1.cat_uid = t2.cat_uid
First off, I apologize for the length. This is kind of complicated (at least for me).
Background on the database:
I have a products, variables, and prices table. "Products" are the main information regarding a product (description, title, etc). "Prices" have information about each price (price, cost, minimum qty required, shipping cost, etc), as some products can have more than one price (a 10" widget is a different price than a 12" widget, for instance). "Variables" are variations to the product that do not change the price, such as color, size, etc.
Initially (when I built this database about 7 years ago) I had the variable information stored in the first price in a list of prices for the same product in a pipe-delimited format (yes, I know, badbadbad). This worked in general, but we've always had a problem, though, where sometimes a variable wouldn't be consistent among all the prices.
For instance, a Widget (product) may be 10" or 12" and sell for $10 and $20 (prices) respectively. However, while the 10" widget may be available in blue and red (variables), the 12" widget is only available in red. We ameliorated this problem by adding a little parenthetical statement in the incongruent variable like "Red (10" ONLY)". This sort of works, but customers are not always that smart and a lot of time is devoted to fixing mistakes when a customer selects a 12" widget in red.
I have since been tasked with modernizing the database and have decided to put the variables in their own table and making them more dynamic and easier to match with certain prices, as well as keep a more dummy-proof inventory (you can't imagine the nightmares).
My first step was to write a stored procedure on my test db (for when I do the conversion) to process all the existing variables into a new variable table (and label table, but that's not really important, I don't think). I effectively parsed out the variables and listed them with the correct product id and the product id they were initially associated with in the variable table. However, I realized this is only a part of the problem, since I (at least for the initial transformation of the database) want each variable to be listed as being connected to each price for a given product.
To do this, I created another table, like so:
tblvariablesprices
variablepriceid | variableid | priceid | productid
which is a many-to-many with the variable table.
Problems:
My problem now is, I don't know how to create the rows. I can create a left join on my prices and variables tables to get (I think) all the necessary data, I just don't know how to go through it. My sql is (mysql 5.0):
SELECT p.priceid, p.productid, variableid, labelid
FROM tblprices p
LEFT JOIN tblvariables v ON p.priceid = v.priceid
ORDER BY productid, priceid
This will get me every priceid and productid and any matching variable and label ids. This is good in certain instances, such as when I have something like:
priceid | productid | variableid | labelid
2 | 7 | 10 | 4
2 | 7 | 11 | 4
2 | 7 | 12 | 4
3 | 7 | (null) | (null) --- another price for product
because now I know that I need to create a record for priceid 2 and variableids 10, 11, 12, and then also for priceid 3 for that product. However, I also get results from this dataset for products with no variables, products with one price and multiple variables, and products with multiple prices and no variables, for instance:
priceid | productid | variableid | labelid
2 | 7 | 10 | 4
2 | 7 | 11 | 4
2 | 7 | 12 | 4
3 | 7 | (null) | (null)
4 | 8 | (null) | (null) --- 1 price no variables
5 | 9 | 13 | 5 --- mult vars, 1 price
5 | 9 | 14 | 5
5 | 9 | 15 | 6
5 | 9 | 16 | 6
6 | 10 | (null) | (null) --- mult price, no vars
7 | 10 | (null) | (null)
8 | 10 | (null) | (null)
Taking the above dataset, I want to add entries into my tblpricesvariables table like so:
variablepriceid | variableid | priceid | productid
1 | 10 | 2 | 7
2 | 11 | 2 | 7
3 | 12 | 2 | 7
4 | 10 | 3 | 7
5 | 11 | 3 | 7
6 | 12 | 3 | 7
7 | 13 | 5 | 9
8 | 14 | 5 | 9
9 | 15 | 5 | 9
10 | 16 | 5 | 9
I have thousands of records to process, so obviously doing this manually is not the answer. Can anyone at least point me in the correct direction, if not come up with a sproc that could handle this type of operation? I also would welcome any comments on how to better organize and/or structure this data.
Thank you so much for reading all this and helping me out.
How about:
SELECT DISTINCT b.variableid, a.priceid, a.productid
FROM tblprices AS a
JOIN tblprices AS b ON a.productid = b.productid
WHERE b.labelid IS NOT NULL
ORDER BY priceid;
+------------+---------+-----------+
| variableid | priceid | productid |
+------------+---------+-----------+
| 10 | 2 | 7 |
| 11 | 2 | 7 |
| 12 | 2 | 7 |
| 10 | 3 | 7 |
| 11 | 3 | 7 |
| 12 | 3 | 7 |
| 13 | 5 | 9 |
| 14 | 5 | 9 |
| 15 | 5 | 9 |
| 16 | 5 | 9 |
+------------+---------+-----------+
INSERTing into tblvariables is left as an exercise for the reader ;)
I think this should work:
SELECT v.variableid, p.productid, p.priceid
FROM tblvariables v, tblprices p
WHERE v.priceid IN (SELECT s.priceid
FROM tblprices s
WHERE s.productid = p.productid);
Next time, can you throw in create and insert statements to replicate your setup? Thanks.