I have a Microsoft Access table with the following values:
id | C | D | ED | T |
---+-------+-----+------------+---+
1 | 33105 | ABC | 2020/01/04 | 1 |
2 | 33105 | ABC | 2020/01/08 | 2 |
3 | 33102 | DEF | 2020/02/01 | 2 |
4 | 34145 | GHI | 2020/02/09 | 1 |
5 | 34145 | GHI | 2020/02/10 | 2 |
6 | 34162 | JKL | 2020/02/08 | 1 |
I would like to extract the rows with the same C but lowest T (with this precedence) and finally sort the results by date (ED) descending. So my expected result is the following:
id | C | D | ED | T |
---+-------+-----+------------+---+
4 | 34145 | GHI | 2020/02/09 | 1 |
6 | 34162 | JKL | 2020/02/08 | 1 |
3 | 33102 | DEF | 2020/02/01 | 2 |
1 | 33105 | ABC | 2020/01/04 | 1 |
What's the fastest way in SQL to do so (the table is actually pretty large)?
You can do it with NOT EXISTS:
SELECT t.*
FROM tablename AS t
WHERE NOT EXISTS (SELECT 1 FROM tablename WHERE C = t.C AND T < t.T)
Or with a correlated subquery:
SELECT t.*
FROM tablename AS t
WHERE t.T = (SELECT MIN(T) FROM tablename WHERE C = t.C)
I have 3 tables as shown:
Video
+----+--------+-----------+
| id | name | videoSize |
+----+--------+-----------+
| 1 | video1 | 1MB |
| 2 | video2 | 2MB |
| 3 | video3 | 3MB |
+----+--------+-----------+
Survey
+----+---------+-----------+
| id | name | questions |
+----+---------+-----------+
| 1 | survey1 | 1 |
| 2 | survey2 | 2 |
| 3 | survey3 | 3 |
+----+---------+-----------+
Sequence
+----+---------+-----------+----------+
| id | videoId | surveyId | sequence |
+----+---------+-----------+----------+
| 1 | null | 1 | 1 |
| 2 | 2 | null | 2 |
| 3 | null | 3 | 3 |
+----+---------+-----------+----------+
I would like to query Sequence and join on both of video and survey tables and merge common columns without specifying the column names (in this case name) like this:
Query Result:
+----+---------+-----------+----------+---------+-----------+-----------+
| id | videoId | surveyId | sequence | name | videoSize | questions |
+----+---------+-----------+----------+---------+-----------+-----------+
| 1 | null | 1 | 1 | survey1 | null | 1 |
| 2 | 2 | null | 2 | video2 | 2MB | null |
| 3 | null | 3 | 3 | survey3 | null | 3 |
+----+---------+-----------+----------+---------+-----------+-----------+
Is this possible?
BTW the below sql doesn't work as it doesn't merge on the name field:
SELECT * FROM "Sequence"
LEFT JOIN "Survey" ON "Survey"."id" = "Sequence"."surveyId"
LEFT JOIN "Video" ON "Video"."id" = "Sequence"."videoId"
This query will show what you want:
select
s.*,
coalesce(y.name, v.name) as name, -- picks the right column
v.videoSize,
y.questions
from sequence s
left join survey y on y.id = s.surveyId
left join video v on v.id = s.videoId
However, the SQL standard requires you to name the columns you want. The only exception being * as shown above.
The data looks similar to this:
+----+------+-----------+-------+---------+---------+--------+
| ID | Unit | Floorplan | Sq Ft | Name | Amenity | Charge |
+----+------+-----------+-------+---------+---------+--------+
| 1 | 110 | A1 | 750 | Alan | GARAGE | 50 |
| 2 | | | | | RENT | 850 |
| 3 | | | | | PEST | 2 |
| 4 | | | | | TRASH | 15 |
| 5 | | | | | TOTAL | 20 |
| 6 | 111 | A2 | 760 | Bill | STORAGE | 35 |
| 7 | | | | | GARAGE | 50 |
| 8 | | | | | RENT | 850 |
| 9 | | | | | PEST | 2 |
| 10 | | | | | TOTAL | 15 |
| 11 | 112 | A3 | 770 | Charlie | PETRENT | 20 |
| 12 | | | | | STORAGE | 35 |
| 13 | | | | | GARAGE | 50 |
| 14 | | | | | RENT | 850 |
| 15 | | | | | TOTAL | 2 |
+----+------+-----------+-------+---------+---------+--------+
I am new to SQL and trying my best using Microsoft Access, but I need help.
The data needs to look like this:
My first step is to separate the units from the rest with
SELECT * FROM table WHERE Unit <> NULL;
and after that I've usually just hard-input the rest.
My idea was as follows:
INSERT INTO table
VALUES (NULL,NULL,...,'Pest',$2)
FROM table
WHERE NOT EXIST 'Pest' BETWEEN x AND y
/* where x = Total 1 and y = Total 2*/
Am I on the right track? I probably need a loop or a join, but I'm not at that level yet.
You can use a crosstab query, though a bit convoluted it is:
TRANSFORM
Sum(TableUnit.Charge) AS SumOfCharge
SELECT
S.Unit,
S.Floorplan,
S.SqFt,
S.Name,
S.Amenity
FROM
TableUnit,
(SELECT
Q.Id,
Val(DMax("Id","TableUnit","Id<=" & Q.[Id] & " And Unit Is Not Null")) AS ParentId
FROM TableUnit As Q) AS T,
(SELECT
TableUnit.Id,
TableUnit.Unit,
TableUnit.Floorplan,
TableUnit.SqFt,
TableUnit.Name,
TableUnit.Amenity
FROM
TableUnit
WHERE
TableUnit.Unit Is Not Null) AS S
WHERE
TableUnit.Id=[T].[Id]
AND
T.ParentId)=[S].[Id]
GROUP BY
T.ParentId,
S.Unit,
S.Floorplan,
S.SqFt,
S.Name,
S.Amenity
PIVOT
TableUnit.Amenity In
("Garage","Pest","Trash","PetRent","Storage","Rent");
Your test data differs a little from your expected output, so:
My MSAccess is rather rusty, but something like this should work:
SELECT t0.Unit, t0.Floorplan, t0.[Sq Ft], t0.Name, t0.Amenity
, SUM(IIF(tM.Amenity = 'GARAGE', Charge, 0)) AS [Garage]
, SUM(IIF(tM.Amenity = 'PEST', Charge, 0)) AS [Pest]
FROM (
SELECT t1.id AS id0, MIN(t2.id) AS idN
FROM t AS t1
INNER JOIN t AS t2 ON t1.id < t2.id
WHERE t1.Unit <> '' AND t2.Unit <> ''
) AS groups
INNER JOIN t AS t0 ON t0.id = groups.id0
LEFT JOIN t AS tM ON tM.id > groups.id0 AND tm.id < groups.idN
GROUP BY t0.Unit, t0.Floorplan, t0.[Sq Ft], t0.Name, t0.Amenity
;
Though, if I remember correctly, and it hasn't changed in newer versions; you can't have true subqueries and will need to make groups a separate query you can join to as if it were a table/view.
I have one table that looks like this:
+---------------+---------------+-----------+-------+------+
| id_instrument | id_data_label | Date | Value | Note |
+---------------+---------------+-----------+-------+------+
| 1 | 57 | 1.10.2010 | 200 | NULL |
| 1 | 57 | 2.10.2010 | 190 | NULL |
| 1 | 57 | 3.10.2010 | 202 | NULL |
| | | | | |
+---------------+---------------+-----------+-------+------+
And the other that looks like this:
+----------------+---------------+---------------+--------------+-------+-----------+------+
| id_fundamental | id_instrument | id_data_label | quarter_code | value | AnnDate | Note |
+----------------+---------------+---------------+--------------+-------+-----------+------+
| 1 | 1 | 20 | 20101 | 3 | 28.2.2010 | NULL |
| 2 | 1 | 20 | 20102 | 4 | 1.8.2010 | NULL |
| 3 | 1 | 20 | 20103 | 5 | 2.11.2010 | NULL |
| | | | | | | |
+----------------+---------------+---------------+--------------+-------+-----------+------+
What I would like to do is to merge/join these two tables in one in a way that I get something like this:
+------------+--------------+--------------+----------+--------------+
| Date | Table1.Value | Table2.Value | AnnDate | quarter_code |
+------------+--------------+--------------+----------+--------------+
| 1.10.2010. | 200 | 3 | 1.8.2010 | 20102 |
| 2.10.2010. | 190 | 3 | 1.8.2010 | 20102 |
| 3.10.2010. | 202 | 3 | 1.8.2010 | 20102 |
| | | | | |
+------------+--------------+--------------+----------+--------------+
So the idea is to order them by Date from Table1 and since Table2 Values only change on the change of AnnDate we populate the Resulting table with same values from Table2.
After that I would like to go through the resulting table and create another (Final table) with the following.
On Date 1.10.2010. take last 4 AnnDates (so it would be 1.8.2010. and f.e. 20.3.2010. 30.1.2010. 15.11.2009) and Table2 values on those AnnDate. Make SUM of those 4 values and then divide the Table1 Value with that SUM.
So we would get something like:
+-----------+---------------------------------------------------------------+
| Date | FinalValue |
+-----------+---------------------------------------------------------------+
| 1.10.2010 | 200/(Table2.Value on 1.8.2010+Table2.Value on 20.3.2010 +...) |
| | |
+-----------+---------------------------------------------------------------+
Is there any way this can be done?
EDIT:
Hmm yes now I see that I really didn't do a good job explaining it.
What I wanted to say is
I try INNER JOIN like this:
SELECT TableOne.Date, TableOne.Value, TableTwo.Value, TableTwo.AnnDate, TableTwo.quarter_code
FROM TableOne
INNER JOIN TableTwo ON TableOne.id_intrument=TableTwo.id_instrument WHERE TableOne.id_data_label = somevalue AND TableTwo.id_data_label = somevalue AND date > xxx AND date < yyy
And this inner join returns 2620*40 rows which means for every AnnDate from table2 it returns all Date from table1.
What I want is to return 2620 values with Dates from Table1
Values from table1 on that date and Values from table2 that respond to that period of dates
f.e.
Table1:
+-------+-------+
| Date | Value |
+-------+-------+
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
+-------+-------+
Table2
+-------+---------+
| Value | AnnDate |
+-------+---------+
| x | 1 |
| y | 4 |
+-------+---------+
Resulting table:
+-------+---------+---------+
| Date | ValueT1 | ValueT2 |
+-------+---------+---------+
| 1 | a | x |
| 2 | b | x |
| 3 | c | x |
| 4 | d | y |
+-------+---------+---------+
You need a JOIN statement for your first query. Try:
SELECT TableOne.Date, TableOne.Value, TableTwo.Value, TableTwo.AnnDate, TableTwo.quarter_code FROM TableOne
INNER JOIN TableTwo
ON TableOne.id_intrument=TableTwo.id_instrument;
I have 3 like with many - many relationship
As:
TABLE 1 : select * from student;
| id | name |
| 1 | sone |
| 2 | stwo |
| 3 | sthree |
| 4 | sfour |
| 6 | ssix |
TABLE 2 : select * from course;
| id | name |
| 100 | CSE |
| 101 | ECE |
| 102 | ITI |
RELATION_SHIP TABLE : select * from student_course
| id | stu_id | cou_id |
| 1 | 1 | 101 |
| 2 | 2 | 102 |
| 3 | 2 | 100 |
| 4 | 3 | 100 |
| 5 | 3 | 101 |
| 6 | 1 | 101 |
| 1 | 6 | 101 |
I need to write a query to select a student with exactly one course 'CSE' and he should not have any other courses.
Thanks in advance
Use query:
SELECT
sc.`stu_id`,
COUNT(sc.`cou_id`) AS cnt
FROM
student_course sc
GROUP BY sc.`stu_id`
HAVING cnt = 1
AND GROUP_CONCAT(cou_id) LIKE
(SELECT
id
FROM
course
WHERE NAME = 'CSE')