I've been given two tables: Employee and Staff
|ID| Name |Surname|Postion| |EmpID|ManID|
---------------------------- -------------
|1 |Scrooge|McDuck |Manager| |3 |1 |
|2 |Daisy |Duck |Manager| |7 |1 |
|3 |Donald |Duck |Support| |6 |2 |
|4 |Minny |Mouse |Support| |4 |2 |
|5 |Mickey |Mouse |Support| |2 |1 |
|6 |Goofy | |Support| |1 |2 |
|7 |Pluto | |Support| |5 |2 |
|8 |Huey |Duck |Support|
|9 |Dewey |Duck |Support|
|10|Louie |Duck |Support|
I am asked for a sql statement that will produce following output
| Name |Surname|Postion|Manager Name|Manager Positon|
------------------------
|Donald |Duck |Support|Scrooge |Manager
|Pluto | |Support|Scrooge |Manager
|Goofy | |Support|Daisy |Manager
|Minny |Mouse |Support|Daisy |Manager
|Daisy |Duck |Support|Scrooge |Manager
|Scrooge|McDuck |Manager|Daisy |Manager
|Mickey |Mouse |Manager|Daisy |Manager
So far I've created a view which displays everything but doesn't create the two new columns and doesn't give the names of the managers.
CREATE VIEW example
AS
SELECT * FROM Employee
JOIN StaffLink
ON Employee.ID = StaffLink.EmpID
SELECT
GO
Please guide me.
SQL:
SELECT Staff.EmpID, Manager.Name AS `Manager Name`,
Manager.Position AS `Manager Position`,
Employee.Name, Employee.Surname, Employee.Position
FROM (Staff, Employee AS Manager, Employee)
WHERE Manager.ID = Staff.ManID AND
Employee.ID = Staff.EmpID;
I believe it is now fixed
Related
I have the following table in Impala.
|LogTime|ClientId|IsNewSession|
|1 |123 |1 |
|2 |123 | |
|3 |123 | |
|3 |666 |1 |
|4 |666 | |
|10 |123 |1 |
|23 |666 |1 |
|24 |666 | |
|25 |444 |1 |
|26 |444 | |
I want to make a new table as follows:
|LogTime|ClientId|IsNewSession|SessionId|
|1 |123 |1 |1 |
|2 |123 | |1 |
|3 |123 | |1 |
|3 |666 |1 |1 |
|4 |666 | |1 |
|10 |123 |1 |2 |
|23 |666 |1 |2 |
|24 |666 | |2 |
|25 |444 |1 |1 |
|26 |444 | |1 |
Basically, I want to make SessionId column that has a unique session ID per set of rows until there's a value of 1 in IsNewSession column after group by ClientId, to differentiate different sessions per ClientId.
I've made IsNewSession column to do so, but not sure how to iterate on the rows to make SessionId column.
Any help would be greatly appreciated!
You can use a cumulative sum:
select t.*,
sum(isnewsession) over (partition by clientid order by logtime) as sessionid
from t;
How can I find the SUM of all scores for the minimum date of each lesson_id please:
-----------------------------------------------------------
|id |uid |group_id |lesson_id |game_id |score |date |
-----------------------------------------------------------
|1 |145 |1 |1 |0 |40 |1391627323 |
|2 |145 |1 |1 |0 |80 |1391627567 |
|3 |145 |1 |2 |0 |40 |1391627323 |
|4 |145 |1 |3 |0 |30 |1391627323 |
|5 |145 |1 |3 |0 |90 |1391627567 |
|6 |145 |1 |4 |0 |20 |1391628000 |
|7 |145 |1 |5 |0 |35 |1391628000 |
-----------------------------------------------------------
I need output:
-------------------
|sum_first_scores |
-------------------
|165 |
-------------------
I have this so far, which lists the score for each minimum date, per lesson, but I need to sum those results as above:
SELECT lesson_id, MIN(date), score AS first_score FROM cdu_user_progress
WHERE cdu_user_progress.uid = 145
GROUP BY lesson_id
You can identify the first score as the one where no earlier record exists. Then just take the sum:
select sum(score)
from edu_user_progress eup
where cdu_user_progress.uid = 145 and
not exists (select 1
from edu_user_progress eup2
where eup2.uid = eup.uid and
eup2.lesson_id = eup.lesson_id and
eup2.date < eup.date
);
This assumes that the minimum date for the lesson id has only one score.
I'm trying to fix my nested query, I have these tables:
cdu_groups_blocks
------------------------
|id |group_id |block_id|
------------------------
|1 |1 |1 |
|2 |1 |2 |
|3 |1 |3 |
------------------------
cdu_blocks: cdu_blocks_sessions:
-------------------------- ---------------------------
|id |name |enabled | |id |block_id |session_id |
-------------------------- ---------------------------
|1 |block_1 |1 | |1 |1 |1 |
|2 |block_2 |1 | |2 |1 |2 |
|3 |block_3 |1 | |3 |2 |3 |
-------------------------- |4 |2 |4 |
|5 |3 |5 |
|6 |3 |6 |
---------------------------
cdu_sessions: cdu_sessions_lessons
-------------------------- ----------------------------
|id |name |enabled | |id |session_id |lesson_id |
-------------------------- ----------------------------
|1 |session_1 |1 | |1 |1 |1 |
|2 |session_2 |1 | |2 |1 |2 |
|3 |session_3 |1 | |3 |2 |3 |
|4 |session_4 |0 | |4 |4 |4 |
|5 |session_5 |1 | |5 |4 |5 |
|6 |session_6 |0 | |6 |5 |6 |
-------------------------- ----------------------------
cdu_lessons:
--------------------------
|id |name |enabled |
--------------------------
|1 |lesson_1 |1 |
|2 |lesson_2 |1 |
|3 |lesson_3 |1 |
|4 |lesson_4 |1 |
|5 |lesson_5 |0 |
|6 |lesson_6 |0 |
--------------------------
It's a many-to-many which links to another many-to-many which links to another many-to-many.
Essentially I want to get all lesson_id(s) associated with a particular group_id.
So far I have this, but it's throwing up various SQL errors:
SELECT b.* FROM
(
SELECT block_id, group_id FROM cdu_groups_blocks
JOIN cdu_blocks ON cdu_blocks.id = cdu_groups_blocks.block_id
WHERE group_id = $group_id
AND enabled = 1
) AS b
INNER JOIN
(
SELECT l.* FROM
(
SELECT session_id, block_id FROM cdu_blocks_sessions
JOIN cdu_sessions ON cdu_sessions.id = cdu_blocks_sessions.session_id
AND enabled = 1
) AS s
INNER JOIN
(
SELECT lesson_id, session_id FROM cdu_sessions_lessons
JOIN cdu_lessons ON cdu_lessons.id = cdu_sessions_lessons.lesson_id
WHERE enabled = 1
) AS l
WHERE s.session_id = l.session_id
) AS sl
WHERE sl.block_id = g.block_id
Any help would be much appreciated!
sl.block_id is from s table in your first select inside sl subselect.
Just get it. Change:
SELECT l.* FROM ...
to
SELECT l.*, s.block_id FROM ...
I have a table with a bunch of scores for lessons, on a user by user basis
------------------------
|uid |lesson_id |score |
------------------------
|1 |0 |20 |
|1 |0 |25 |
|1 |0 |15 |
|1 |0 |40 |
|1 |1 |70 |
|1 |0 |10 |
|1 |1 |20 |
|1 |1 |55 |
|1 |1 |55 |
|1 |0 |5 |
|1 |2 |65 |
------------------------
I also have a table of all possible lessons that can be scored:
------------
|lesson_id |
------------
|0 |
|1 |
|2 |
|3 |
|4 |
|5 |
------------
I need to calculate the maximum score for each lesson in the second table from the scores in the first table, and take an average of that over the number of lessons in the second table:
So, the maximum scores for the scores table are (for user 1):
-----------------------
|lesson_id |max_score |
-----------------------
|0 |40 |
|1 |70 |
|2 |65 |
-----------------------
I need to sum them: 175 and divide by the total number of lessons in table 2: 6 which should give the answer 29.16
Any ideas how to do this in a single statement?
I can get the average of all max values for the scores table (for user 1) like so:
SELECT AVG(max_score) AS avg_max_score FROM
(
SELECT uid, lesson_id, MAX(score) AS max_score FROM cdu_user_progress
AND uid =1
GROUP BY lesson_id
) AS m
SELECT
AVG(max_score)
FROM
(
SELECT
lesson.lesson_id,
max(isNull(score,0)) as max_score
FROM
lesson
LEFT JOIN
cdu_user_progress
ON
lesson.lesson_id = cdu_user_progress.lesson_id
GROUP BY
lesson.lesson_id
) AS m
I need to get the sum of the scores for the first of each lesson_id, but I also need the overall min and max scores for all lesson_ids as well as some other info:
cdu_groups:
----------------
|id |name |
----------------
|1 |group_1 |
|2 |group_2 |
----------------
cdu_user_progress145:
-----------------------------------------------------------
|id |uid |group_id |lesson_id |game_id |score |date |
-----------------------------------------------------------
|1 |145 |1 |1 |0 |40 |1391627323 |
|2 |145 |1 |1 |0 |80 |1391627567 |
|3 |145 |1 |2 |0 |40 |1391627323 |
|4 |145 |1 |3 |0 |30 |1391627323 |
|5 |145 |1 |3 |0 |90 |1391627567 |
|6 |145 |1 |4 |0 |20 |1391627323 |
|7 |145 |1 |5 |0 |35 |1391627323 |
-----------------------------------------------------------
I need this output:
-----------------------------------------------------------------
|name |group_id |min_score |max_score |... |sum_first_scores |
-----------------------------------------------------------------
|group_1 |1 |20 |90 |... |165 |
-----------------------------------------------------------------
SELECT
cdu_groups.*,
MAX(score) AS max_score,
MIN(score) AS min_score,
COUNT(DISTINCT(lesson_id)) AS scored_lesson_count,
COUNT(DISTINCT CASE WHEN score >= 75 then lesson_Id ELSE NULL END) as passed_lesson_count,
SUM(first_scores.first_score) AS sum_first_scores
FROM cdu_user_progress
JOIN cdu_groups ON cdu_groups.id = cdu_user_progress.group_id
JOIN
(
SELECT lesson_id, MIN(date), score AS first_score FROM cdu_user_progress
WHERE cdu_user_progress.uid = 145
GROUP BY lesson_id
) AS first_scores ON first_scores.lesson_id = cdu_user_progress.lesson_id
WHERE cdu_user_progress.uid = 145
I'm getting this error though:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SUM(first_scores.first_score) AS sum_first_scores FROM cdu_user_progress ' at line 7