If I have 4 tables (Army, Navy, Air Force, Marines), all have serial number as primary key, and name. And I have a table operation which has op_num as primary key and op_name. I also have a table operation member, which associates the operation table to other 4 tables, how can I write a single SQL statement, return the names of the members (regardless of branch of service) of the covert operation 'Desert Storm' using Microsoft T-SQL syntax?
Given that your association table looks like this
Operation_Member (op_num, ser_num)
the following query should return the desired result:
SELECT Soldier.Name FROM Operation_Member
INNER JOIN Operation
ON Operation.op_num = Operation_Member.op_num
INNER JOIN
(
SELECT ser_num, name FROM Army
UNION ALL
SELECT ser_num, name FROM Navy
UNION ALL
SELECT ser_num, name FROM Air_Force
UNION ALL
SELECT ser_num, name FROM Marines
) Soldier
ON Soldier.ser_num = Operation_Member.ser_num
WHERE Operation.op_name = 'Desert Storm'
Related
I have two tables with the following rows
Table A (transaction)
Order Seller Customer
1 300 500
Table B (Persons)
PersonID FullName
300 Peter White
500 Scott Bold
I want a result like this
Order Seller Customer FullName (Seller) FullName (customer)
1 300 500 Peter White Scott Bold
I've tried multiple things however which makes more sense is a join a table twice, however I'm getting:
Ambiguous column name
This is SQL Server 2019.
Basically I'm looking to retrieve info from the same table instead of creating additional tables. Is that possible? If yes, how do you do? Thank you in advance.
As #jarlh wrote in comment:
select t.order, t.seller, t.customer, sel.fullname, cust.fullname
from transaction t
join persons sel -- sel is an alias to persons table
on sel.personid = t.seller
join persons cust
on cust.personid = t.customer;
Query with join will return the result as long as both seller and customer exist in persons table -- here it should as source table names transactions :).
I have another form of query it still join table B twice.
This is archaic syntax which I don't recommend but for beginner know the concept of JOIN:
select t.*,B.FullName as FullName (customer) from
(
select A.Order,A.Seller,A.Customer,B.FullName as FullName(Seller)
from A,B where A.Seller=B.PersionID
) t, B where t.Customer=B.PersionID
The proper way of JOIN:
select t.*,B.FullName as FullName (customer) from
(
select A.Order,A.Seller,A.Customer,B.FullName as FullName(Seller)
from A JOIN B ON A.Seller=B.PersionID
) t JOIN B ON t.Customer=B.PersionID
Hoping this can help you.
So in one table I can use a replace and charindex to extract a specific ID that relates to a PK in another table, I want to then join the data from the other table based on the trimmed value, how can I do this?
select top 100 *, Replace(Left(LogValue,Charindex(';', LogValue) - 1) ,'RtaId=', '') as TaskID, PrmRoutingTask.*
from SytLog
inner join PrmRoutingTask on RtaId = TaskID
where LogTableName like '%Routing%' and LogValue like '%RtaAniId=397%'
order by 5 desc;
The problem I get is that the temp column name I create (TaskID) is not working in the inner join where in fact the results of TaskID have the reference to the RtaId in the RoutingTask table.
Assuming LogValue belongs to the first table you can use the column named TaskID if you produce a subquery as a table expression of the main query.
For example you can produce the column in the table expression a by doing:
select top 100
a.*,
PrmRoutingTask.*
from (
select *,
Replace(Left(LogValue,Charindex(';', LogValue) - 1) ,'RtaId=', '') as TaskID
from SytLog
) a
inner join PrmRoutingTask on PrmRoutingTask.RtaId = a.TaskID
where LogTableName like '%Routing%'
and LogValue like '%RtaAniId=397%'
order by 5 desc
I have a table UserParent:
Id, FirstName, LastName
I have a table UserChild:
Id, ParentUserId (FK), ChildAttributeX
I have the following sample SQL:
SELECT Id, 0 ChildUserId, FirstName, LastName, NULL FROM UserParent
UNION
SELECT ParentUserId, Id, FirstName, LastName, ChildAttributeX FROM UserChild
Some Users may exist in both tables. All Users are stored with basic info in UserParent although some Users who have ChildAttributeX will have a FK ref to the UserParent in UserChild along with the ChildAttributeX in UserChild.
How can I resolve this as part of a UNION or some other SQL technique so all Users are included in the result set, without duplicate users?
I think this is what you are looking for. If all records must exist in parent table, this will return all records from parent, and any record that exist in child table, but only unique records (DISTINCT does that).
SELECT DISTINCT UP.ID, UP.FirstName, UP.LastName
FROM UserParent UP
LEFT OUTER JOIN UserChild UC ON UP.ID = UC.ParentUserID
If you are looking for all the records present in both table, you can try below query:
SELECT
coalesce(UP.Id,UC.ParentUserId),
0 ChildUserId,
(UP.FirstName,UC.FirstName),
(UP.LastName,UC.LastName),
NULL FROM
UserParent UP
FULL OUTER JOIN
UserChild UC
ON UC.ParentUserId = UP.ID
I was trying to update table columns from another table.
In person table, there can be multiple contact persons with same inst_id.
I have a firm table, which will have latest 2 contact details from person table.
I am expecting the firm tables as below:
If there is only one contact person, update person1 and email1. If there are 2, update both. If there is 3, discard the 3rd one.
Can someone help me on this?
This should work:
;with cte (rn, id, inst_id, person_name, email) as (
select row_number() over (partition by inst_id order by id) rn, *
from person
)
update f
set
person1 = cte1.person_name,
email1 = cte1.email,
person2 = cte2.person_name,
email2 = cte2.email
from firm f
left join cte cte1 on f.inst_id = cte1.inst_id and cte1.rn = 1
left join cte cte2 on f.inst_id = cte2.inst_id and cte2.rn = 2
The common table expression (cte) used as a source for the update numbers rows in the person table, partitioned by inst_id, and then the update joins the cte twice (for top 1 and top 2).
Sample SQL Fiddle
I think you don't have to bother yourself with this update, if you rethink your database structure. One great advantage of relational databases is, that you don't need to store the same data several times in several tables, but have one single table for one kind of data (like the person's table in your case) and then reference it (by relationships or foreign keys for example).
So what does this mean for your example? I suggest, to create a institution's table where you insert two attributes like contactperson1 and contactperson2: but dont't insert all the contact details (like email and name), just the primary key of the person and make it a foreign key.
So you got a table 'Person', that should look something like this:
ID INSTITUTION_ID NAME EMAIL
1 100 abc abc#inst.com
2 101 efg efg#xym.com
3 101 ijk ijk#fg.com
4 101 rtw rtw#rtw.com
...
And a table "Institution" like:
ID CONTACTPERSON1 CONTACTPERSON2
100 1 NULL
101 2 3
...
If you now want to change the email adress, just update the person's table. You don't need to update the firm's table.
And how do you get your desired "table" with the two contact persons' details? Just make a query:
SELECT i.id, p1.name, p1.email, p2.name, p2.email
FROM institution i LEFT OUTER JOIN person p1 ON (i.contactperson1 = p1.id)
LEFT OUTER JOIN person p2 ON (i.contactperson2 = p2.id)
If you need this query often and access it like a "table" just store it as a view.
I'm trying to determine a correct way to isolate rows within a table that have the same values in 2 columns.
There are two tables, one (Name) with the person's names and IDs, and the other one (Nation) with people's IDs and their nations. I join the two tables with inner join, and now the new table columns consist of an ID, first name, last name, and nation. If I want to find pairs of people who have the same last name and are from the same nation, why isn't
select ID, FName, LName, Nation
from (Name inner join Nation on Name.ID = Nation.ID)
group by Name, Nation
having count(Name) > 1 and count(Nation) > 1
working?
I'm aiming for the result to be a table with columns:
ID -------First--------------- Last ---------Nation
where the last names and nations will be identical pairs while first names will be different.
I feel like the group by part isnt appropriate, but is there even an alternate way? Thanks for any help.
If you are using MS SQL Server:
select
*
from
(
select
Name.*,
Nation.Nation,
cnt = count(*) over(partition by LName, Nation)
from Name
join Nation on Nation.ID = Name.ID
) t
where cnt > 1
Try this:
SELECT * FROM (
SELECT Name.ID, Name.FName, Name.LName, Nation.Nation
FROM Name
INNER JOIN Nation ON (Name.ID = Nation.ID)
) a
INNER JOIN (
SELECT Name.ID, Name.FName, Name.LName, Nation.Nation
FROM Name
INNER JOIN Nation ON (Name.ID = Nation.ID)
) b ON (a.LName = b.LName AND a.Nation = b.Nation)
WHERE a.ID < b.ID
As Simon Righarts hinted, something's not right with the design.
Scenario 1)
If a name can have multiple nations, you would have 3 tables implementing an n:m relationship.
CREATE TABLE name (name_id int, name text, ...);
CREATE TABLE nation (nation_id int, nation text, ...);
CREATE TABLE nationality (name_id int references name(name_id)
,nation_id int references nation(nation_id)
... );
Query for the scenario:
SELECT a.name_id, a.fname, a.lname, n.nation
FROM name a
JOIN nationality na USING (name_id)
JOIN nation n USING (nation_id)
JOIN (
SELECT a.lname, na.nation_id
FROM name a
JOIN nationality na USING (name_id)
GROUP BY 1,2
HAVING count(*) > 1) x USING (lname, nation_id)
Scenario 2)
If a name can only have one nation, there would be a column nation_id in the table name:
CREATE TABLE name (name_id int
,name text
,nation_id int references nation(nation_id), ...);
CREATE TABLE nation (nation_id int, nation text, ...);
Query for this scenario:
SELECT a.name_id, a.fname, a.lname, n.nation
FROM name a
JOIN nation n USING (nation_id)
JOIN (
SELECT a.lname, a.nation_id
FROM name a
GROUP BY 1,2
HAVING count(*) > 1) x USING (lname, nation_id);
All multiple occurrences are included here, not just "pairs" - assuming you meant that.
Your actual description doesn't fit either scenario.