I have an old database with some complex joining of the data. As given below
Subjects
Id Name
-------------------------------
1 Math
2 Science
3 English
Results
Id StudentId Math MathMax Science ScienceMax English EnglishMax TotalMarks Max
-----------------------------------------------------------------------------------------
1 81 5 10 6 10 3 10 14 30
2 82 8 10 8 10 9 10 25 30
3 83 7 10 8 10 7 10 22 30
Now I am trying to convert it to more easy and readable database. So I come up with the tables like
Results
ResultId StudentId TotalMarks MaxMarks
-------------------------------------------
1 81 14 30
2 82 25 30
3 83 22 30
ResultDetails
Id ResultId SubjectId Marks MaxMarks
--------------------------------------------------------
1 1 1 5 10
2 1 2 6 10
3 1 3 7 10
& so one
Now the real question I can insert data in the new Results table but I am confused on the second table. I can't understand that how to pass column name of one table and get the id of that name from second table and insert it in the third one.
I am trying on but can't understand the right commands to achieve this. My database already have 50000+ records and I have to merge them according to this new tables.
Assuming this is a one-off conversion of data, and you've already populated your new Results table, something as simple as the following should work:
INSERT INTO ResultDetails(ResultId, SubjectId, Marks, MaxMarks)
SELECT
R.StudentId,
1 AS SubjectId,
OldR.Math AS Marks,
OldR.MathMax AS MaxMarks
FROM Results R
INNER JOIN OldResults OldR ON R.StudentId = OldR.StudentId
INSERT INTO ResultDetails(ResultId, SubjectId, Marks, MaxMarks)
SELECT
R.StudentId,
2 AS SubjectId,
OldR.Science AS Marks,
OldR.ScienceMax AS MaxMarks
FROM Results R
INNER JOIN OldResults OldR ON R.StudentId = OldR.StudentId
INSERT INTO ResultDetails(ResultId, SubjectId, Marks, MaxMarks)
SELECT
R.StudentId,
3 AS SubjectId,
OldR.English AS Marks,
OldR.EnglishMax AS MaxMarks
FROM Results R
INNER JOIN OldResults OldR ON R.StudentId = OldR.StudentId
It's not a very elegant solution, but it doesn't need to be for a one-off conversion.
Related
This question already has answers here:
How do I create a comma-separated list using a SQL query?
(11 answers)
Closed 18 days ago.
I have a table that contains a bunch of keys with different IDs. Some keys have more than 1 ID.
ID Table:
key id
a 1
a 11
a 12
b 2
c 3
c 33
2nd table:
key count location
a 17 123 Test Rd
b 10 12 Smith St
c 18 999 Fire Rd
Desired result:
key count location id
a 17 123 Test Rd 1, 11, 12
b 10 12 Smith St 2
c 18 999 Fire Rd 3, 33
I am trying to join this table with another table that I have so that the ID is carried over, but the issue I am running in to is that my join result is getting a larger number of rows than desired simply because it is creating a row for each unique ID that a key has. Is there a way to do the JOIN in a way where it groups each id together (perhaps comma delimited) in one single row?
You can use STRING_AGG:
SELECT t.key, s.count, s.location, STRING_AGG(t.id, ',') as id
FROM YourTable t
JOIN YourTable2 s
ON(t.key = s.key)
GROUP BY t.key, s.count, s.location
Here are the very simplified versions of my three tables.
Schools_Subjects Table
SchoolId
SubjectId
1
2
5
1
5
6
The above table contains only parent subject IDs.
Subjects Table
SubjectId
Name
ParentSubjectId
1
Science
{NULL}
2
Mathematics
{NULL}
3
Biology
1
4
Physics
1
5
Chemistry
1
6
History
{NULL}
7
Elementary Math
2
8
Calculus
2
Questions Table
QuestionId
Text
SubjectId
1
What is 2 + 2
7
2
Tell me the fastest animal name
3
3
Salt is composed of which two elements
5
4
How to divide 6 apples among 3 students
7
I want to fetch all the questions given a (or multiple) school ID. For example for schoolId:5, I have the below SQL query:
SELECT *
FROM Questions
WHERE SubjectId IN (
SELECT SubjectId
FROM Subjects
WHERE ParentSubjectId IN (
SELECT SubjectId
FROM Schools_Subjects
WHERE SchoolId = 5
)
)
My above query works but I want to change it into a JOIN format query.
I work on SQL Server, but a ANSI-SQL query will be highly appreciated.
If using Mysql:
SELECT Q.*
FROM Questions Q
JOIN (
SELECT S.SubjectId
FROM Subjects S
JOIN Schools_Subjects SS
ON S.ParentSubjectId = SS.SubjectId AND SS.SchoolId = 5
) t1
ON Q.SubjectID = t1.SubjectId
QuestionId Text SubjectId X
1 2 Tell me the fastest animal name 3 NA
2 3 Salt is composed of which two elements 5 NA
Which is the same results produced by your code
I have two table and have to fill in a list of missing values in one of the table based on the other one. First table has student's information and the second table has Grade related info, Grade and Grade description.
Table One
ID Name yearWithUs Grade Course Level
1 Jim 2004 4 4
2 Jim 2004 4 1
2 Jim 2003 3 3
4 Jim 2002 2 3
4 Jim 2002 2 1
3 Jim 2001 1 2
3 Jim 2001 1 1
Table two -- logic is.. A Student in a higher Course Level can change to a lower Course Level at anytime during the semester. And It can only go downward 1 level at a time. Example: Jim in his second grade first was assigned to attend course in level 3. He need to attend course in level 2 first before he can attend course in level 1. Means. Row for course level 2 at jim's first grade is missing.
Table Two
ID Grade Grade_Desc Course Level Course Desc
1 1 First Grade 1 Basic
2 1 First Grade 2 Normal
3 1 First Grade 3 Hard
4 1 First Grade 4 Expert
5 2 Second Grade 1
6 2 Second Grade 2
7 2 Second Grade 3
8 2 Second Grade 4
. . .
. . .
. . .
Logic of Table Two
ID Grade Grade_Desc Course Level Possible Move
1 1 First Grade 1 Null
2 1 First Grade 2 1
3 1 First Grade 3 2
4 1 First Grade 4 3
Ouptput one ... how to use select statement to return Jim's Grade?
ID Name Grade_Desc Grade yerWithUs Course Level
1 Jim Fourth Grade 4 2004 4
2 Jim Fourth Grade 4 2004 3
3 Jim Fourth Grade 4 2004 2
4 Jim Fourth Grade 4 2004 1
5 Jim Third Grade 3 2003 3
6 Jim Second Grade 2 2002 3
7 Jim Second Grade 2 2002 2
8 Jim Second Grade 2 2002 1
9 Jim First Grade 2 2001 2
10 Jim First Grade 2 2001 1
Output Two..How to retrieve only the missing row into a new temp table?
ID Name Grade_Desc Grade yearWithUs Course Level
2 Jim Fourth Grade 4 2004 3
3 Jim Fourth Grade 4 2004 2
7 Jim Second Grade 2 2002 2
I am currently is using a messy Cursor Statement to do it. The structure looks really messy and hard to debug return errors. I did a lot of research, and saw people use Cross Join to fill the missing portion which looks really clean (See example below)... I have tried the script it myself in many different way by using the cross join example below...obviously, I failed. I found a similar question in stackoverflow..but I am not able to understand how does it work and why without looking at the data....I need help to understand how to use cross join to rerun missing row? and I am open to any other possible solution.
"SELECT calendar.Date,
Category.Cat,
Score = ISNULL(Scores.Score, 0)
FROM Calendar
CROSS JOIN Catogory
LEFT JOIN Scores
ON Scores.Cat = Category.Cat
AND Scores.Date = Calendar.Date
WHERE Calendar.DayOfMonth = 1;"
Inserting missing rows with a join
Thank You
This will produce that output:
select distinct name, grade, Grade_Desc
from one
cross join two
If select is all you want then:
Select row_number() over(order by (select 1)) as id, * from
(Select distinct name from t1)t1
cross join t2
Here is fiddle http://sqlfiddle.com/#!6/a8a42/3
Try this out:
Create #Temp
DECLARE #Name VARCHAR(100) = 'Jim'
SELECT ROW_NUMBER() OVER (ORDER BY B.Grade DESC,B.CourseLevel DESC) ID,
A.Name,
B.Grade_Desc,
B.Grade,
A.YearWithUs,
B.[Course Level]
INTO #temp
FROM
(
SELECT DISTINCT Name,YearWithUs,Grade
FROM TableOne
WHERE Name = #Name
) A
INNER JOIN TableTwo B
ON A.Grade = B.Grade
Output One
SELECT *
FROM #temp
Output Two into #OutputTwo(temp table)
SELECT A.* INTO #OutputTwo
FROM #temp A
LEFT JOIN TableOne B
ON A.Grade = B.Grade
AND A.[Course Level] = B.[Course Level]
WHERE A.Grade IS NULL AND A.[Course Level] IS NULL
I have 2 tables: Persons(idPerson INT) and Questions(idQuestion INT).
I want to insert the data into a 3rd table: OrderedQuestions(idPerson INT, idQuestion INT, questionRank INT)
I want to assign all the questions to all the persons but in a random order.
I thought of doing a CROSS JOIN but then, I get the same order of questions for every persons.
INSERT INTO OrderedQuestions
SELECT idPerson, idQuestion, questionRank FROM Persons
CROSS JOIN
(SELECT idQuestion,ROW_NUMBER() OVER (ORDER BY NEWID()) as questionRank
FROM Questions) as t
How can I achieve such a random, distinct ordering for every persons?
Obviously, I want the solution to be as fast as possible.
(It can be done using TSQL or Linq to SQL)
Desired results for 3 persons and 5 questions:
idPerson idQuestion questionRank
1. 1 18 1
2. 1 14 2
3. 1 25 3
4. 1 31 4
5. 1 2 5
6. 2 2 1
7. 2 25 2
8. 2 31 3
9. 2 18 4
10. 2 14 5
11. 3 31 1
12. 3 18 2
13. 3 14 3
14. 3 25 4
15. 3 2 5
I just edited the results (Since the IDs are autogenerated, they can't be used to order the questions).
This could probably be written more efficently, but it meets all the reqs.
SELECT
idperson,
idQuestion,
ROW_NUMBER() OVER (PARTITION BY personid ORDER BY ordering) as questionRank
FROM (
SELECT idperson, idQuestion, ordering
FROM person
CROSS JOIN
(
SELECT idQuestion, NewID() as ordering FROM Question
) as t
) as a
order by personid, QuestionRank
I've searched for adding multiple AVG calculations and have found a few entries, however I'm having to join another table and the examples of that are scarce.
closest answer I can find is this
but it deals with dates and no joins
here are my tables:
indicators:
StandardScore IndicatorID NID DID
0.033333 7 1 1
0.907723 9 1 1
0.574739 26 1 1
0.917391 21 1 1
.....
indexindicators:
IndexID IndicatorID
1 7
1 26
2 21
3 7
4 9
4 21
4 7
5 9
.......
My goal is to get the average for each IndexID (indexindicators) related to NID/DID (indicators) combination
a query to retrieve a single value would be
SELECT AVG(StandardScore) FROM `indicators` INNER JOIN indexindicators ON indicators.IndicatorId=indexindicators.IndicatorId WHERE nid=1 AND did=1 AND indexindicators.IndexId=1
ultimately there will be 6 (indexID) averages which then have to be rounded then * by 100 (should I do that part with PHP?)
This seems like such a simple query, but i just can't seem wrap my mind around it.
Thanks in advance for your help!
SELECT nid, did, indexid, 100.0 * AVG(StandardScore)
FROM 'indicators'
INNER JOIN 'indexindicators'
ON indicators.IndicatorId=indexindicators.IndicatorId
group by nid, did, indexid