Select two tables side by side - sql

I have two tables filled with two files of which table1 always has one row more than the second.
I want to merge the two tables into one. When I use a right join e.g.
select *
from table2
right join table1 on table1.id = table2.id and table1.eq_nb = table2.eq_nb
I will have the 4 combinations for eq_nb = 25 because it is repeated two times.
But I rather want to stick the columns side by side
To know, I don't have conditions on arrival and depart time of each eq_nb (I can't add something like datediff(second,table1.arrival_time,table2.depart_time) < X )
table1:
id | eq_nb | arival_time
-------------------------------------
1 | 25 | 05:30:15.231
-------------------------------------
2 | 50 | 06:30:15.231
-------------------------------------
3 | 7 | 07:30:15.231
-------------------------------------
1 | 25 | 08:30:15.231
-------------------------------------
5 | 27 | 09:30:15.231
-------------------------------------
table2:
id | eq_nb | depart_time
----------------------------------
1 | 25 | 05:31:15.231
----------------------------------
2 | 50 | 06:31:15.231
----------------------------------
3 | 7 | 07:31:15.231
----------------------------------
1 | 25 | 08:31:15.231
----------------------------------
desired result:
id | eq_nb | arrival_time | depart_time
-------------------------------------------------------
1 | 25 | 05:30:15.231 | 05:31:15.231
-------------------------------------------------------
2 | 50 | 06:30:15.231 | 06:31:15.231
-------------------------------------------------------
3 | 7 | 07:30:15.231 | 07:31:15.231
-------------------------------------------------------
1 | 25 | 08:30:15.231 | 08:31:15.231
--------------------------------------------------------
5 | 27 | 09:30:15.231 | NULL
--------------------------------------------------------

left join should do what you want:
select *
from table1 t1 left join
table2 t2
on t1.id = t2.id and t1.eq_nb = t2.eq_nb;
Given your data, the ids are unique, so there should be no duplication. Note: This is equivalent to your first query; left join is typically easier to follow because all the rows in the first table are in the result set.
Here is a db<>fiddle, illustrating that it works.

Related

Update rows in one table depending on a column in another table

I have 2 tables in different databases in SQL Server.
database1.table_A
id | name | present |
-----|------------|-----------|
1 | jon | 1 |
2 | ham | 0 |
3 | sam | 1 |
7 | tom | 1 |
database2.table_B
absentid |
----------|
1 |
5 |
7 |
For every id value present in table_B, I want the value of present in table_A to be 0. So, my final result should look like -
id | name | present |
-----|------------|-----------|
1 | jon | 0 |
2 | ham | 0 |
3 | sam | 1 |
7 | tom | 0 |
I want to confirm if the following query I wrote is correct or if there are any better ways to do this:
update database1.table_A
set present=0
FROM database1.table_A t1
inner join
database2.table_B t2
ON t1.id = t2.absentid;
If you want to set present = 1 if they are not in the table, then you would use left join:
update t1
set present = (case when t2.absentid is null then 1 else 0 end)
from database1.table_A t1 left join
database2.table_B t2
on t1.id = t2.absentid;
Otherwise, if you want to keep the value in that case, your version is fine.

SQL : Comparing multiple values in one table with a single value in another Table

I have two tables Table 1 and Table 2
Table 1:
-------------------------------
| Ser | StartDate | Activity |
-------------------------------
| 1 | 2002-10-13 | 1 |
| 1 | 2002-10-13 | 2 |
| 1 | 2007-09-04 | 3 |
Table 2:
------------------------
|Ser|DateOfRegistration|
------------------------
| 1 | 2002-10-12 |
| 1 | 2007-09-02 |
Now, the result that I want is such that for Activity 1 and 2 the Date of registration should be before the Start Date and difference between the dates must be the least. Similarly, for Activity 3, the date of registration for Activity 3 should be before the start date. The result should look like this.
Table 3:
--------------------------------------------
|Ser|StartDate |DateofRegistration|Activity|
--------------------------------------------
| 1 |2002-10-13| 2002-10-12 | 1 |
| 1 |2002-10-13| 2002-10-12 | 2 |
| 1 |2002-09-04| 2002-09-02 | 3 |
How can I join Table 1 and 2 to get Table 3?
You can use outer apply:
select t1.*, t2.dateofregistration
from table1 t1 outer apply
(select top (1) t2.*
from table2 t2
where t2.ser = t1.ser and t2.dateofregistration < t1.startdate
order by t2.dateofregistration desc
) t2

Check if data for update is same as before in SQL Server

I have a table Table1:
ID | RefID | Answer | Points |
----+-------+---------+--------+
1 | 1 | 1 | 5 |
2 | 1 | 2 | 0 |
3 | 1 | 3 | 3 |
4 | 2 | 1 | 4 |
I have a result set in temp table Temp1 with same structure and have update Table1 only if for refID answer and points have changed, otherwise there should be deletion for this record.
I tried:
update table1
set table1.answer = temp1.answer,
table1.points = temp1.points
from table1
join temp1 on table1.refid = temp1.refid
where table1.answer != temp1.answer or table1.points != temp1.points
Here is a fiddle http://sqlfiddle.com/#!18/60424/1/1
However this is not working and don't know how to add the delete condition.
Desired result should be if tables not the same ex. (second row answer 2 points3):
ID | RefID | Answer | Points |
----+-------+---------+--------+
1 | 1 | 1 | 5 |
2 | 1 | 2 | 3 |
3 | 1 | 3 | 3 |
4 | 2 | 1 | 4 |
if they are same all records with refID are deleted.
Explanation when temp1 has this data
ID | RefID | Answer | Points |
----+-------+---------+--------+
12 | 1 | 1 | 5 |
13 | 1 | 2 | 0 |
14 | 1 | 3 | 3 |
EDIT: adding another id column questionid solved the update by adding this also in join.
Table structure is now:
ID | RefID | Qid |Answer | Points |
----+-------+------+-------+--------+
1 | 1 | 10 | 1 | 5 |
2 | 1 | 11 | 2 | 0 |
3 | 1 | 12 | 3 | 3 |
4 | 2 | 11 | 1 | 4 |
SQL for update is: (fiddle http://sqlfiddle.com/#!18/00f87/1/1) :
update table1
set table1.answer = temp1.answer,
table1.points = temp1.points
from table1
join temp1 on table1.refid = temp1.refid and table1.qid = temp1.qid
where table1.answer != temp1.answer or table1.points != temp1.points;
SELECT ID, refid, answer, points
FROM table1
How can I make the deletion case, if data is same ?
You need to add one more condition in the join to exactly match the column.Try this one.
update table1
set table1.answer=temp1.answer,
table1.points=temp1.points
from
table1 join temp1 on table1.refid=temp1.refid and **table1.ID=temp1.ID**
where table1.answer!=temp1.answer or table1.points!=temp1.points
I would first do the delete, and only then the update.
The reason for this is that once you've deleted all the records where the three columns are the same, your update statement becomes simpler - you only need the join, and no where clause:
DELETE t1
FROM table1 AS t1
JOIN temp1 ON t1.refid = temp1.refid
AND t1.qid = temp1.qid
AND t1.answer=temp1.answer
AND t1.points=temp1.points
UPDATE t1
SET answer = temp1.answer,
points = temp1.points
FROM table1 AS t1
JOIN temp1 ON t1.refid=temp1.refid
AND t1.qid = temp1.qid
I think from what i understood that you need to use id instead of refid or both if id is unique

Query returned with an extra column in sql -ms access

So I am wondering. I fell into an interesting suggestion from another developer. So i basically have two tables I join in a query and I want the resulting table from the query to have an extra column that comes from the table on from the joint.
Example:
#table A: contains rating of players, changes randomly at any date depending
#on drop of form from the players
PID| Rating | DateChange |
1 | 2 | 10-May-2014 |
1 | 4 | 20-May-2015 |
1 | 20 | 1-June-2015 |
2 | 4 | 1-April-2014|
3 | 4 | 5-April-2014|
2 | 3 | 3-May-2015 |
#Table B: contains match sheets. Every player has a different match sheet
#and plays different dates.
MsID | PID | MatchDate | Win |
1 | 2 | 10-May-2014 | No |
2 | 1 | 15-May-2015 | Yes |
3 | 3 | 10-Apr-2014 | No |
4 | 1 | 21-Apr-2015 | Yes |
5 | 1 | 3-June-2015 | Yes |
6 | 2 | 5-May-2015 | No |
#I am trying to achieve this by running the ms-access query: i want to get
#every players rating at the time the match was played not his current
#rating.
MsID | PID | MatchDate | Rating |
1 | 2 | 10-May-2014 | 4 |
2 | 1 | 15-May-2015 | 2 |
3 | 3 | 10-Apr-2014 | 4 |
4 | 1 | 21-Apr-2015 | 4 |
5 | 1 | 3-June-2015 | 20 |
6 | 2 | 5-May-2015 | 3 |
This is what I have tried below:
Select MsID, PID, MatchDate, A-table.rating as Rating from B-table
left Join A-table
on B-table.PID = A-table.PID
where B-table.MatchDate > A-table.Datechange;
any help is appreciated. The solution can be in Vba as long as it returns something like a view/table I can manipulate using other queries or report.
Think of this in terms of sets of data... you need a set that lists the MAX dateChange for each player's and match date.
Soo...
SELECT MAX(A.DateChange) MDC, A.PID, B.Matchdate
FROM B-table B
INNER Join A-table A
on B.PID = A.PID
and A.DateChange <= B.MatchDate
GROUP BY A.PID, B.Matchdate
Now we take this and join it back to what you've done to limit the results in table A and B to ONLY those with that date player and matchDate (my inline table C)
SELECT B.MsID, B.PID, B.MatchDate, A.rating as Rating
FROM [B-table] B
INNER JOIN [A-table] A
on B.PID = A.PID
INNER JOIN (
SELECT MAX(Y.DateChange) MDC, Y.PID, Z.Matchdate
FROM [B-table] Z
INNER Join [A-table] Y
on Z.PID = Y.PID
and Y.DateChange <= Z.MatchDate
GROUP BY Y.PID, Z.Matchdate) C
on C.mdc = A.DateChange
and A.PID = C.PId
and B.MatchDate = C.Matchdate
I didn't create a sample for this using your data so it's untested but I believe the logic is sound...
Now Tested! SQL Fiddle using SQL server though...
My results don't match yours exactly. I think you're expected results are wrong though for MSID 4 given rules defined.

Oracle ordering by several same meaning columns

I have to make sortable table like this:
Sortable table:
building_id | building_age | title |
-------------------------------------------------
1 | 100 | New york buil |
2 | 50 | House 1 |
3 | 50 | House 10 |
From these tables:
Building Table:
building_id | building_age | building_type_1_FK | building_type_2_FK
---------------------------------------------------------
1 | 100 | null | 1
2 | 50 | 1 | null
3 | 50 | 2 | null
building_type_1:
type_id | title | diff1 |
-------------------------------------------------
1 | New york buil| blablabla |
building_type_2:
building_id | title |
----------------------------
1 | House 1 |
2 | House 10 |
3 | House 500 |
While joining these tables I get several title columns where one of them is not null. Is there any way to sort by title and select top 10 results without fetching all the data and then sorting in the app?
p.s.. I know that in general this architecture is not good, but I can't change it.
Yes. You want to do a left outer join to the two tables, and then bring the results together:
select b.building_id, b.building_age, coalesce(bt1.title, bt2.title) as title
from building b left outer join
building_type_1 bt1
on b.building_type_1_FK = bt1.type_id left outer join
building_type_2 bt2
on b.building_type_2_FK = bt2.building_id;
To get the top 10 results in Oracle:
select *
from (select b.building_id, b.building_age, coalesce(bt1.title, bt2.title) as title
from building b left outer join
building_type_1 bt1
on b.building_type_1_FK = bt1.type_id left outer join
building_type_2 bt2
on b.building_type_2_FK = bt2.building_id
order by title
) b
where rownum <= 10;