I have the following Table. What I want to get is the missing combinations of Student, Class, Book. I have a query below that does it, but I would like others to provide more efficient queries (ie possibly ones that use group by) to find the missing combos.
SQL FIDDLE HERE - http://sqlfiddle.com/#!6/16e2b/3
StudentBook Table
+---------+---------+--------------+
| Student | Class | Book |
+---------+---------+--------------+
| Albert | Math | AlgebraBook |
| Albert | Math | FractionBook |
| Bridget | Math | AlgebraBook |
| Bridget | Math | FractionBook |
| Charles | Math | AlgebraBook |
| Charles | Math | FractionBook |
| Debbie | English | NovelBook |
| Debbie | English | PoemBook |
| Edward | English | PoemBook |
| Frank | English | PoemBook |
+---------+---------+--------------+
The following Rows in the Set are the missing combinations
Correct Result of My Query Below
+---------+---------+-----------+
| Student | Class | Book |
+---------+---------+-----------+
| Edward | English | NovelBook |
| Frank | English | NovelBook |
+---------+---------+-----------+
And I can use the following Query to get the Missing Combinations, but I want a faster more efficient solutions. Basically I'm looking for other more Effective Techniques, such as possibly using Group By.
WITH CTE_ClassBooks AS
(
SELECT DISTINCT Class, Book FROM StudentBook
),
CTE_StudentClasses AS
(
SELECT DISTINCT Student, Class FROM StudentBook
),
CTE_CombosOfStudentClassBooks AS
(
SELECT DISTINCT b.Student, a.Class, a.Book
FROM CTE_ClassBooks a
INNER JOIN CTE_StudentClasses b ON a.Class = B.Class
)
SELECT * FROM CTE_CombosOfStudentClassBooks
EXCEPT
SELECT * FROM StudentBook
This might be a little faster, your route doesn't seem terribly inefficient though.
;WITH cte AS (SELECT DISTINCT Class,Book FROM Table1)
SELECT b.Student,a.*
FROM cte a
JOIN Table1 b
ON a.Class = b.Class
LEFT JOIN Table1 c
ON a.Class = c.CLass
AND a.Book = c.Book
AND b.Student = c.Student
WHERE c.Class IS NULL
Demo: SQL Fiddle
SELECT S1.STUDENT,S1.CLASS,S2.BOOK FROM
STUDENTBOOK S1,(SELECT DISTINCT CLASS,BOOK FROM STUDENTBOOK) S2
WHERE S1.CLASS = S2.CLASS
AND S1.BOOK <> S2.BOOK
EXCEPT
SELECT STUDENT,CLASS,BOOK FROM STUDENTBOOK
Related
edit : Sorry gurus, I have to rephrase my question since I forgot there are 3 tables in one query.
I have three tables with tbl_goods ,tbl_units and tbl_sat which looks like this :
tbl_goods, consists of sold goods
+--------+-------+-------+-------+
| goods |code |qty |unit |
+--------+-------+-------+-------+
| cigar | G001 | 1 | pack |
| cigar | G001 | 2 | pcs |
| bread | G002 | 2 | pcs |
| soap | G003 | 1 | pcs |
+--------+-------+-------+-------+
and tbl_units as below :
+--------+-------------+-------+
| code |ucode |qty |
+--------+-------------+-------+
| KG001 | U001 | 10 |
+--------+-------------+-------+
I add letter 'K' in front of code in tbl_units to differ and make sure not collide with code in tbl_goods.
and tbl_sat as below :
+--------+-------------+
| ucode | unit |
+--------+-------------+
| U001 | pack |
+--------+-------------+
| U002 | box |
+--------+-------------+
| U003 | crate | etc
so only cigar will have conversion because table units have the code
what the result I need to show as below :
+--------+-------+-------+-------+--------+
| goods |code |qty |unit | total |
+--------+-------+-------+-------+--------+
| cigar | G001 | 1 | pack | 10 |
| cigar | G001 | 2 | pcs | 2 |
| bread | G002 | 2 | pcs | 2 |
| soap | G003 | 1 | pcs | 1 |
+--------+-------+-------+-------+--------+
so if the code in goods doesn't have match in tbl_units then it will show just as qty in tbl_goods, but if they match then it will convert multiply from tbl_units
Thank you very much..really appreciated
regards
EDIT (might worked ?) :
I try to modify from #danielpr query, and this is the result
think it worked, please help to check it out
SELECT j.code,j.qty ,j.unit, IIF(j.unit=t.unit,j.qty*u.qty,j.fqty) FROM tbl_goods j
LEFT JOIN tbl_units u on u.code ='K' || j.code
LEFT JOIN tbl_sat t ON t.ucode =u.ucode [WHERE j.code='G001']
GROUP BY j.code,j.qty
[WHERE ..] optional if omitted will list all items, but if I just want to check the cigar..just put WHERE CLAUSE
If I understand correct, you are looking for a combination of LEFT JOIN and CASE WHEN or COALESCE.
Here the CASE WHEN option:
SELECT g.goods, g.code, g.qty, g.unit,
CASE WHEN u.conversion IS NULL
THEN g.qty
ELSE g.qty * u.qty
END AS total
FROM
tbl_goods g
LEFT JOIN tbl_units u
ON g.code = u.code
AND g.unit = u.conversion;
As said, COALESCE could also do and is a bit shorter:
SELECT g.goods, g.code, g.qty, g.unit,
g.qty * COALESCE(u.qty,1) AS total
FROM
tbl_goods g
LEFT JOIN tbl_units u
ON g.code = u.code
AND g.unit = u.conversion;
But I think this option has a worse readability compared to CASE WHEN.
Therefore, I would prefer CASE WHEN here.
Try out: db<>fiddle
EDIT because the authour changed the question:
According to the new description, a further table is involved and the table structure is other than described before. So, the COALESCE option is not possible at all in this case.
We require the CASE WHEN way here:
SELECT g.goods, g.code, g.qty, g.unit,
CASE WHEN u.qty IS NULL OR u.ucode IS NULL OR t.unit IS NULL
THEN g.qty
ELSE g.qty * u.qty
END AS total
FROM
tbl_goods g
LEFT JOIN tbl_units u ON u.code = CONCAT('K', g.code)
LEFT JOIN tbl_sat t ON u.ucode = t.ucode AND g.unit = t.unit;
New sample fiddle for this new situation: db<>fiddle
SELECT
tbl_goods.goods
, tbl_goods.code
, tbl_goods.qty
, tbl_goods.unit
, IF(tbl_goods.unit=tbl_units.conversion,tbl_goods.qty*tbl_units.qty,tbl_goods.qty) total
FROM tbl_goods
LEFT JOIN tbl_units ON tbl_goods.code=tbl_units.code
on total column, we can match whether the unit in tbl_goods is same with tbl_units, which is pack.
If it is the same, then we multiply the pack qty in tbl_units with the pack in tbl_goods, else, just return the qty of tbl_goods.
I'm honestly not sure how to title this - so apologies if it is unclear.
I have two tables I need to compare. One table contains tree names and nodes that belong to that tree. Each Tree_name/Tree_node combo will have its own line. For example:
Table: treenode
| TREE_NAME | TREE_NODE |
|-----------|-----------|
| 1 | A |
| 1 | B |
| 1 | C |
| 1 | D |
| 1 | E |
| 2 | A |
| 2 | B |
| 2 | D |
| 3 | C |
| 3 | D |
| 3 | E |
| 3 | F |
I have another table that contains names of queries and what tree_nodes they use. Example:
Table: queryrecord
| QUERY | TREE_NODE |
|---------|-----------|
| Alpha | A |
| Alpha | B |
| Alpha | D |
| BRAVO | A |
| BRAVO | B |
| BRAVO | D |
| CHARLIE | A |
| CHARLIE | B |
| CHARLIE | F |
I need to create an SQL where I input the QUERY name, and it returns any ‘TREE_NAME’ that includes all the nodes associated with the query. So if I input ‘ALPHA’, it would return TREE_NAME 1 & 2. If I ask it for CHARLIE, it would return nothing.
I only have read access, and don’t believe I can create temp tables, so I’m not sure if this is possible. Any advice would be amazing. Thank you!
You can use group by and having as follows:
Select t.tree_name
From tree_node t
join query_record q
on t.tree_node = q.tree_node
WHERE q.query = 'ALPHA'
Group by t.tree_name
Having count(distinct t.tree_node)
= (Select count(distinct q.tree_node) query_record q WHERE q.query = 'ALPHA');
Using an IN condition (a semi-join, which saves time over a join):
with prep (tree_node) as (select tree_node from queryrecord where query = :q)
select tree_name
from treenode
where tree_node in (select tree_node from prep)
group by tree_name
having count(*) = (select count(*) from prep)
;
:q in the prep subquery (in the with clause) is the bind variable to which you will assign the various QUERY values at runtime.
EDIT
I don't generally set up the test case on online engines; but in a comment below this answer, the OP said the query didn't work for him. So, I set up the example on SQLFiddle, here:
http://sqlfiddle.com/#!4/b575e/2
A couple of notes: for some reason, SQLFiddle thinks table names should be at most eight characters, so I had to change the second table name to queryrec (instead of queryrecord). I changed the name in the query, too, of course. And, second, I don't know how I can give bind values on SQLFiddle; I hard-coded the name 'Alpha'. (Note also that in the OP's sample data, this query value is not capitalized, while the other two are; of course, text values in SQL are case sensitive, so one should pay attention when testing.)
You can do this with a join and aggregation. The trick is to count the number of nodes in query_record before joining:
select qr.query, t.tree_name
from (select qr.*,
count(*) over (partition by query) as num_tree_node
from query_record qr
) qr join
tree_node t
on t.tree_node = qr.tree_node
where qr.query = 'ALPHA'
group by qr.query, t.tree_name, qr.num_tree_node
having count(*) = qr.num_tree_node;
Here is a db<>fiddle.
I have the following data:
select * from art_skills_table;
+----+------+---------------------------+
| ID | Name | skills |
+----+------+---------------------------|
| 1 | Anna | ["painting","photography"]|
| 2 | Bob | ["drawing","sculpting"] |
| 3 | Cat | ["pastel"] |
+----+------+---------------------------+
select * from computer_table;
+------+------+-------------------------+
| ID | Name | skills |
+------+------+-------------------------+
| 1 | Anna | ["word","typing"] |
| 2 | Cat | ["code","editing"] |
| 3 | Bob | ["excel","code"] |
+------+------+-------------------------+
I would like to write an SQL statement which results in the following table.
+------+------+-----------------------------------------------+
| ID | Name | skills |
+------+------+-----------------------------------------------+
| 1 | Anna | ["painting","photography","word","typing"] |
| 2 | Bob | ["drawing","sculpting","excel","code"] |
| 3 | Cat | ["pastel","code","editing"] |
+------+------+-----------------------------------------------+
I've tried something like SELECT * from art_skills_table LEFT JOIN computer_table ON name. However it doesn't give what I need. I've read about array_cat but I'm having a bit of trouble implementing it.
if the skills column from both tables are arrays, then you should be able to get away with this:
SELECT a.ID, a.name, array_cat(a.skills, c.skills)
FROM art_skills_table a LEFT JOIN computer_table c
ON c.id = a.id
That said, While you used LEFT join in your sample, I think either an INNER or FULL (OUTER) join might serve you better.
First, i wondered why the data are stored in such a model.
Was of the opinion that NoSQL databases lack ability for joins and ...
... a semantic triple would be in the form of subject–predicate–object.
... a Key-value (KV) stores use associative arrays.
... a relational database would be normalized.
A few information about the use case would have helped.
Nevertheless, you can select the data with CONCAT and REPLACE for the desired form.
SELECT art_skills_table.ID, computer_table.name,
CONCAT(
REPLACE(art_skills_table.skills, '}',','),
REPLACE(computer_table.skills, '{','')
)
FROM art_skills_table JOIN computer_table ON art_skills_table.ID = computer_table.ID
The query returns the following result:
+----+------+--------------------------------------------+
| ID | Name | Skills |
+----+------+--------------------------------------------+
| 1 | Anna | {"painting","photography","word","typing"} |
| 2 | Cat | {"drawing","sculpting","code","editing"} |
| 3 | Bob | {"pastel","excel","code"} |
+----+------+--------------------------------------------+
I've used the ID for the JOIN, even though Bob has different values.
The JOIN should probably be done over the name.
JOIN computer_table ON art_skills_table.Name = computer_table.Name
BTW, you need to tell us what SQL engine you're running on.
I'm struggling with getting data from 7 different sql-tables without receiving too many rows.
I have the following (simple) query which retrieves data from 7 different tables:
SELECT h.name, h.address, h.zipcode, h.city, h.association, r.name_de, f.first_name, f.last_name, f.email, p.year, j.name
FROM `tx_gipdhotels_domain_model_hotel` AS h
JOIN `tx_gipdhotels_hotel_jobs_mm` AS hj ON h.uid = hj.uid_local
JOIN `tx_gipdhotels_domain_model_jobs` AS j ON j.uid = hj.uid_foreign
JOIN `tx_gipdhotels_hotel_participations_mm` AS hp ON h.uid = hp.uid_local
JOIN `tx_gipdhotels_domain_model_participations` AS p ON p.uid = hp.uid_foreign
JOIN `tx_gipdhotels_domain_model_region` AS r ON r.uid = h.region
JOIN `fe_users` AS f ON f.uid = h.feuser
As you can see there are two many-to-many-relationships between the tables. These two tables aren't related (except through the h table). Now the problem is that this results in receiving a row for each possible combination of these mm-tables.
Example:
table 1 hotel
|-----------|------------|----------|----------|
| uid | name | jobs | part |
|...........|............|..........|..........|
| 1 | ab | 3 | 2 |
| | | | |
table 2 jobs
|-----------|------------|
| uid | name |
|...........|............|
| 1 | tech |
| 2 | cs |
| 3 | perf |
| | |
table 3 part
|-----------|------------|
| uid | name |
|...........|............|
| 1 | abcd |
| 2 | efgh |
| | |
With this combination (including mm-tables for hotel_jobs and hotel_part) I would receive 6 rows for one hotel only and in each row only one value would differ from another row:
result:
|-----------|------------|----------|----------|
| uid | name | job | part |
|...........|............|..........|..........|
| 1 | ab | tech | abcd |
| 1 | ab | tech | defg |
| 1 | ab | cs | abcd |
| 1 | ab | cs | defg |
| 1 | ab | perf | abcd |
| 1 | ab | perf | defg |
| | | | |
It would be lovely if I could retrieve this data in one single row like the following:
wanted result:
|-----------|------------|--------------------|----------------|
| uid | name | job | part |
|...........|............|....................|................|
| 1 | ab | tech, cs, perf | abcd, efgh |
| | | | |
I can't figure out how to get the wanted result, it exceeds my experience and knowledge so I'm asking you, do you know how to achieve this with a single query?
I've googled quite a bit and I have found the STUFF() method but it's not supported in MariaDB. In some question here on stack someone has done something similar with a cast but I didn't understand it too well and I didn't know how to adapt this to my problem...
I'm using MariaDB and the query will be made from php. There is no way of changing the data structure of the tables.
Any help and explanations would be greatly appreciated.
I hope this will work, try it, if there is any error, we are gonna fix it.
SELECT
h.name,
h.address,
h.zipcode,
h.city,
h.association,
GROUP_CONCAT(DISTINCT p.year SEPARATOR ', '),
GROUP_CONCAT(DISTINCT j.name SEPARATOR ', '),
r.name_de,
f.first_name,
f.last_name,
f.email,
h.tstamp,
h.crdate
FROM tx_gipleasedisturbhotels_domain_model_hotel AS h
JOIN `tx_gipleasedisturbhotels_hotel_jobs_mm` AS hj
ON h.uid = hj.uid_local
JOIN `tx_gipleasedisturbhotels_domain_model_jobs` AS j
ON j.uid = hj.uid_foreign
JOIN `tx_gipleasedisturbhotels_hotel_participations_mm` AS hp
ON h.uid = hp.uid_local
JOIN `tx_gipleasedisturbhotels_domain_model_participations` AS p
ON p.uid = hp.uid_foreign
JOIN `tx_gipleasedisturbhotels_domain_model_region` AS r
ON r.uid = h.region
JOIN `fe_users` AS f
ON f.uid = h.feuser
GROUP BY h.name
ORDER BY h.name ASC
Thanks to #jarlh I found the solution:
SELECT h.name, h.address, h.zipcode, h.city, h.association,
GROUP_CONCAT(DISTINCT p.year SEPARATOR ', '),
GROUP_CONCAT(DISTINCT j.name SEPARATOR ', '),
r.name_de, f.first_name, f.last_name, f.email, h.tstamp, h.crdate
FROM `tx_gipleasedisturbhotels_domain_model_hotel` AS h
JOIN `tx_gipleasedisturbhotels_hotel_jobs_mm` AS hj ON h.uid = hj.uid_local
JOIN `tx_gipleasedisturbhotels_domain_model_jobs` AS j ON j.uid = hj.uid_foreign
JOIN `tx_gipleasedisturbhotels_hotel_participations_mm` AS hp ON h.uid = hp.uid_local
JOIN `tx_gipleasedisturbhotels_domain_model_participations` AS p ON p.uid = hp.uid_foreign
JOIN `tx_gipleasedisturbhotels_domain_model_region` AS r ON r.uid = h.region
JOIN `fe_users` AS f ON f.uid = h.feuser
GROUP BY h.name
ORDER BY h.name ASC
It's a combination of GROUP_CONCAT and GROUP BY. It has to be grouped by the field which you want to have only once. To get all mm-values to one single cell you'll have to use GROUP_CONCAT on those fields in the SELECT statement.
With this query I receive the wanted result. Maybe this will be helpful to someone else as well. ;)
Here are the two tables i have: [all columns in both tables are of type "text"], Table name and the column names are in bold fonts.
Names
--------------------------------
Name | DoB | Team |
--------------------------------
Harry | 3/12/85 | England
Kevin | 8/07/86 | England
James | 5/05/89 | England
Scores
------------------------
ScoreName | Score
------------------------
James-1 | 120
Harry-1 | 30
Harry-2 | 40
James-2 | 56
End result i need is a table that has the following
NameScores
---------------------------------------------
Name | DoB | Team | ScoreData
---------------------------------------------
Harry | 3/12/85 | England | "{"ScoreName":"Harry-1", "Score":"30"}, {"ScoreName":"Harry-2", "Score":"40"}"
Kevin | 8/07/86 | England | null
James | 5/05/89 | England | "{"ScoreName":"James-1", "Score":"120"}, {"ScoreName":"James-2", "Score":"56"}"
I need to do this using a single SQL command which i will use to create a materialized view.
I have gotten as far as realising that it will involve a combination of string_agg, JOIN and JSON, but haven't been able to crack it fully. Please help :)
I don't think the join is tricky. The complication is building the JSON object:
select n.name, n.dob, n.team,
json_agg(json_build_object('ScoreName', s.name,
'Score', s.score)) as ScoreData
from names n left join
scores s
ons.name like concat(s.name, '-', '%')
group by n.name, n.dob, n.team;
Note: json_build_object() was introduced in Postgres 9.4.
EDIT:
I think you can add a case statement to get the simple NULL:
(case when s.name is null then NULL
else json_agg(json_build_object('ScoreName', s.name,
'Score', s.score))
end) as ScoreData
Use json_agg() with row_to_json() to aggregate scores data into a json value:
select n.*, json_agg(row_to_json(s)) "ScoreData"
from "Names" n
left join "Scores" s
on n."Name" = regexp_replace(s."ScoreName", '(.*)-.*', '\1')
group by 1, 2, 3;
Name | DoB | Team | ScoreData
-------+---------+---------+---------------------------------------------------------------------------
Harry | 3/12/85 | England | [{"ScoreName":"Harry-1","Score":30}, {"ScoreName":"Harry-2","Score":40}]
James | 5/05/89 | England | [{"ScoreName":"James-1","Score":120}, {"ScoreName":"James-2","Score":56}]
Kevin | 8/07/86 | England | [null]
(3 rows)