Matching Different Value within One Row

Matching Different Value within One Row - mysql

I want to perform a query whereby I want to check whether on the columns A has either certain values. A could have only X , X and Y or a combination of X Y and Z.
To give a better understanding. I am checking a book's author within a table itself. The table has the BOOK_ID , BOOK_TITLE , AUTHOR_NAME, AUTHOR_ORDER.
So a book might have 1,2 or 3 authors, listed in order written inside the AUTHOR_ORDER row. I am trying very hard to reach an output where if a book has 3 authors, it will display accordingly from the first author to the third author. I am now stuck in the part where I need to compare the value and present it in the output.
Any idea how to achieve this in MYSQL output?
Sample :
The output result is more or less like this:
If the title has au_ord of 1,2 and 3, there shall be a new column with all the authors name listed in ascending.
So for example, for title BU1032, the Author row will be Bennet, Green

I think GROUP_CONCAT is what you are after:
SELECT Title_ID,
Title,
GROUP_CONCAT(au_LName ORDER BY au_Ord) AS Authors
FROM Books
GROUP BY Title_ID, Title;
SQL FIDDLE

Related

Search query MS Access

I have a database as follows
The first column is the name.
The second column bears the number of the son in the family.
The third column is the family Code.
-Explanatory information:
-The first column in the database. Contains the name of the father and children and they are not arranged
-The second column in the database. It contains the number of fathers and children in the database where the parents take nothing and the children take numbers.
-The third column in the database. It contains a code that is specific to each family and does not subscribe to any other family.
What is required when searching in query as follows:
The query is made for a specific name, where the search is for displaying all fields containing the same name if it is for a father or children.
Provided that the final form of the offer is to collect parents only and arrange them in ascending order.
The data in the images is for illustration and the actual column names of the query
If you search for a name, let it be Ali, the result will be as follows 2 image:
2- The final result With the order of the parents in ascending name order.
MY TRY NOT WORK
SELECT PARENT_NAME, PARENT_NUMBER,PARENT_CODE
FROM PARENT_TB
HAVING (((PARENT_NUMBER) Is Null));

Try using a subquery:
SELECT
IIF(PARENT_NUMBER Is Null,
PARENT_NAME,
(Select T.PARENT_NAME
From PARENT_TB As T
Where T.PARENT_CODE = PARENT_TB.PARENT_CODE And T.PARENT_NUMBER Is Null)) As ParentName,
PARENT_CODE
FROM
PARENT_TB
WHERE
PARENT_NUMBER = "Ali"

MySQL finding all elements that have the same value in column A but different values in cloumn B

I'm fairly new to SQL and have a question regarding a query.
I have a database with various pictures attached to a product. All these pictures have a prediction. The structure is like this:
product_ id picture_id prediction
1------------pic1.jpg----------type a
1------------pic2.jpg----------type b
1------------pic3.jpg----------type b
2------------pic4.jpg----------type a
2------------pic5.jpg----------type a
2------------pic6.jpg----------type a
3------------pic7.jpg----------type c
...
... so on.
Each pictures is predicted individually and because of that some of the products have contradictory predictions (meaning that on the same products some pictures are predicted type a while others are predcited type b).
I want to filter out all of these products with a query. In other words: I need all product_ids where the predictions for the pictures linked to it are not all the same. In our example I want it only to show me product 1.
I tried some stuff with GROUP BY, but have not yet gotten anywhere near the result that I want.
Thanks for helping,
Cheers

Use COUNT(DISTINCT prediction) to get the number of different predictions. It will be more than 1 for the products with different predictions.
SELECT product_id
FROM yourTable
GROUP BY product_id
HAVING COUNT(DISTINCT prediction) > 1

Complex MySQL query is giving incorrect results

Note: You can find the previous question and its answer here. A deep testing on it proved the previous answer is incorrect: Writing a Complex MySQL Query
I have 3 tables.
Table Words_Learned contains all the words known by a user, and the order in which the words were learned. It has 3 columns 1) word ID and 2)user id and 3) order in which the word was learned.
Table Article contains the articles. It has 3 columns 1) article ID, 2) unique word count and 3) article contents.
Table Words contains a list of all unique words contained in each article. It has 2 columns 1) word ID and 2) article ID
The database diagram is as below/
Now, using this database and using "only" mysql, I need to do the below work.
Given a user ID, it should get a list of all words known by this user, sorted in the revese order from which they were learned. In other words, the most recently learned words will be at the top of the list.
Let’s say that a query on a user ID shows that they’ve memorized the following 3 words, and we track the order in which they’ve learned the words.
Octopus - 3
Dog - 2
Spoon - 1
First we get a list of all articles containing the word Octopus, and then do the calculation using table Words on just those articles. Calculation means if that article contains more than 10 words that do not appear in the user’s vocabulary list (pulled from table words_learned), then it is excluded from the listing.
Then, we do a query for all records that contain dog, but DO NOT contain “octopus”
Then, we do a query for all records that contain spoon, but DO NOT contain the words Octopus or Dog
And you keep doing this repetitive process until we’ve found 100 records that meet this criteria.
To achieve this process, I did the below (Please visit the SQLFiddle link to see the table structures, test data and my query)
http://sqlfiddle.com/#!2/48dae/1
In my query, you can see the generated results and they are invalid. But on a "Proper Query", the result should be,
Level 1
Level 1
Level 1
Level 2
Level 2
Level 2
Level 3
Level 3
Here is a phudocode for better understanding.
Do while articles found < 100
{
for each ($X as known words, in order that those words were learned)
{
Select all articles that contain the word $X, where the 1) article has not been included in any previous loops, and 2)where the count of "unknown" words is less than 10.
Keep these articles in order.
}
}

select * from (
select a.idArticle, a.content, max(`order`) max_order
from words_learned wl
join words w on w.idwords = wl.idwords
join article a on a.idArticle = w.idArticle
where wl.userId = 4
group by a.idArticle
) a
left join (
select count(*) unknown_count, w2.idArticle from words w2
left join words_learned wl2 on wl2.idwords = w2.idwords
and wl2.userId = 4
where wl2.idwords is null
group by w2.idArticle
) unknown_counts on unknown_counts.idArticle = a.idArticle
where unknown_count is null or unknown_count < 10
order by max_order desc
limit 100
http://sqlfiddle.com/#!2/6944b/9
The first derived table selects unique articles a given user knows one or more words from as well as the maximum order value of those words. The maximum order value is used to sort the final results so that articles containing high order words appear first.
The second derived table counts the number of words a given user doesn't know for each article. This table is used to exclude any articles that contain 10 or more words the user doesn't know.