I'm using SQL Server 2017 and I have a question on how to return specific values (I'm not sure 100% if I should be using joins or subqueries.) I tried to put an example below of what I'm trying to do and hopefully someone can help me out with this.
I have two tables below:
Table 1
Record
Topic
100
History
101
Science
102
Art
103
Music
Table 2
Record
Course
100
Intro
100
Intermediate
101
Intermediate
101
Advanced
102
Intro
102
Intermediate
103
Intermediate
103
Advanced
I want to join the two tables together, but only bring back the columns 'Record' and 'Topic' ONLY where the Record DOES NOT have an 'Intro' course attached to it.
So I would want to bring back the following results (since both Courses do not have an Intro class):
Record
Topic
101
Science
103
Music
So far I've had no luck and am bringing back more records than I should so any help or guidance would be appreciated. Thank you in advance.
You could use exists logic here:
SELECT Record, Topic
FROM Table1 t1
WHERE NOT EXISTS (
SELECT 1
FROM Table2 t2
WHRE t2.Record = t1.Record AND
t2.Course = 'Intro'
);
Related
I am trying to work with two tables on BigQuery. From table1 I want to find the accession ID of all records that are "World", and then from each of those accession numbers I want to create a column with every name in a separate row. Unfortunately, when I run this:
Select name
From `table2`
Where acc IN (Select acc
From `table1`
WHERE source = 'World')
Instead of getting something like this:
Acc1
Acc2
Acc3
Jeff
Jeff
Ted
Chris
Ted
Blake
Rob
Jack
Jack
I get something more like this:
row
name
1
Jeff
2
Chris
3
Rob
4
Jack
5
Jeff
6
Jack
7
Ted
8
Blake
Ultimately, I am hoping to download the data and somehow use python or something to take each name and count the number of times it shows up with each other name at a given accession number, and furthermore measure the degree to which each pairing is also found with third names in any given column, i.e. the degree to which they share a cohort. So I need to preserve the groupings which exist with each accession number, but I am struggling to find info on how one might do this.
Could anybody point me in the right direct for this, or otherwise is the way I am going about this wise if that is my end goal?
Thanks!
This is not a direct answer to the question you asked. In general, it is easier to handle multiple rows rather than multiple columns.
So, I would recommend that you put each acc value in a separate row and then list the names as an array:
select t2.acc, array_agg(t2.name order by t2.name) as names
from `table2` t2
where t2.acc in (Select t1.acc
From `table1` t1
where t1.source = 'World'
)
group by t2.acc;
Otherwise, you are going to have a challenge just naming the columns in your result set.
I have got the following 3 fields in a file: person_ows person_is_owed amount
Example content:
Bob John 100
John Bob 110
What does a SQL look like that produces:
Bob John 100 110
John Bob 110 100
Sorry if this is a trivial question, but I am just trying to learn SQL and I find it really like HELL!
So, what you need is to be able to JOIN two rows. In this case you'll probably want an OUTER JOIN assuming that there isn't always a match of each owing the other. Now you just need to come up with your JOIN criteria, which in this case is going to be based on the names (person_owes and person_is_owed):
SELECT
T1.person_owes,
T1.person_is_owed,
T1.amount AS owes_amount,
COALESCE(T2.amount, 0) AS is_owed_amount
FROM
My_Table T1
LEFT OUTER JOIN My_Table T2 ON T2.person_is_owed = T1.person_owes
The COALESCE is just to make sure that when there is no match that you get a value of 0 instead of NULL.
Also, this assumes that there is only going to be one of each combination of person_owes and person_is_owed. If you might have two rows showing that John owes Bill two different amounts of money then you would have to adjust the SQL above and it would be a bit more complex.
If you plan to use SQL much then you should invest the time in reading one (or preferably more) beginning books on the subject.
Assuming that the combination of (person_ows, person_is_owed) is unique
select person_ows,
person_is_owed,
amount,
(select t2.amount
from the_table t2
where (t2.person_ows, t2.person_is_owed) = (t1.person_is_owed, t1.person_ows))
from the_table t1
I am using MS Access and I have a rather complex situation.
I have Respondents who are linked to varying numbers of different Companies via 2 connecting tables. I want to be able to create a list of distinct customers which excludes any customer associated with Company X.
Here is a pic of the relationships that are involved with the query.
And here is an example of what I'm trying to achieve.
RespondentRef | Respondent Name
8 Joe Bloggs
.
RespondentRef | GroupRef
8 2
.
GroupRef | CompanyRef
2 10
.
CompanyRef | CompanyName
10 Ball of String
I want a query where I enter in 'Ball of String' for the company name, and then it produces a list of all the Respondents (taken from Tbl_Respondent) which completely excludes Respondent 8 (as he is linked to CompanyName: Ball of String).
Tbl_Respondent
RespondentRef | Respondent Name
... ...
7 Bob Carlyle
9 Anton Boyle
I have tried many combinations of subqueries with <> and NOT EXISTS and NOT IN and nothing seems to work. I suspect the way these tables are linked may have something to do with it.
Any help you could offer would be very much appreciated. If you have any questions let me know. (I have made best efforts, but please accept my apologies for any formatting conventions or etiquette faux-pas I may have committed.)
Thank you very much.
EDIT:
My formatted version of Frazz's code is still turning resulting in a syntax error. Any help would be appreciated.
SELECT *
FROM Tbl_Respondent
WHERE RespondentRef NOT IN (
SELECT tbl_Group_Details_Respondents.RespondentRef
FROM tbl_Group_Details_Respondents
JOIN tbl_Group_Details ON tbl_Group_Details.GroupReference = tbl_Group_Details_Respondents.GroupReference
JOIN tbl_Company_Details ON tbl_Company_Details.CompanyReference = tbl_Group_Details.CompanyReference
WHERE tbl_Company_Details.CompanyName = "Ball of String"
)
This should do what you need:
SELECT *
FROM Tbl_Respondent
WHERE RespondentRef NOT IN (
SELECT gdr.RespondentRef
FROM Tbl_Group_Details_Respondent gdr
JOIN Tbl_Group_Details gd ON gd.GroupRef=gdr.GroupRef
JOIN Tbl_Company_Details cd ON cd.CompanyRef=gd.CompanyRef
WHERE cd.CompanyName='Ball of String'
)
If anyone can help
I have two tables like this:
field.tab1
111
1110
1111
1112
field.tab2
111
I need to update table 2 like this:
field.tab2
1113
Thank you for your quick response and guidance
Yes I'm new here and in sql, access too, I have those two tables that i need to compare and make the field from second table to have unique records because will be appended to the first table, so this is what i've done in access:
SELECT tab2.field, tab1.field, tab1.field1, tab2.field1
FROM tab2 LEFT JOIN tab1 ON tab2.field=tab1.field;
and manualy increase every tab1.field :) until tab2.field and tab2.field1 become null, where field is the number of client and field1 number of order.
The natural answer to this question is:
update field.tab2
set col = 1113
where col = 111;
I am using a MS SQL db and I have 3 tables: 'base_info', 'messages', 'config'
bases:
ID Name NameNum
====================================
1 Home 101
2 Castle 102
3 Car 103
messages:
ID Signal RecBy HQ
============================
111 120 Home 1
111 110 Castle 1
111 125 Car 1
222 120 Home 2
222 125 Castle 2
222 130 Car 2
333 100 Home 1
333 110 Car 2
config:
ID SignalRec SignalOut RecBy HQ
====================================
111 60 45 101 1
111 40 60 102 1
222 50 60 102 2
222 30 90 101 2
333 80 10 103 1
Ok so now I have a subquery in which I select the 'SignalRec' and 'SignalOut' from the config table and match it on the messages table by ID and Date(not included above), the problem is that I need it to match where messages.RecBy = config.RecBy but config.RecBy is a string but it's equivalent Name is in the bases table. So I almost need to do a subquery inside a subquery or some type of join and compare the returned value.
Here is what I have so far:
(SELECT TOP 1 config.SignalRec from config WHERE config.ID = messages.ID AND ||I need th other comparison here||...Order By...) As cfgSignalRec,
(SELECT TOP 1 config.SignalOut from config WHERE config.ID = messages.ID AND ||I need th other comparison here||...Order By...) As cfgSignalOut
I tried to make this as clear as possible but if you need more info let me know.
I would normalize out RecBy in your messages table to reference the bases table. Why would you insert the string content there if it's also referenced in bases?
This is exactly why normalization exists: reduce redundancy, reduce ambiguity, and enforce referential integrity.
To make this more clear, RecBy in the messages table should be a foreign key to Bases.
I think this could do the trick (although I have not tried it...)
SELECT
c.SignalRec
FROM config c
INNER JOIN bases b
ON c.RecBy = b.NameNum
INNER JOIN messages m
ON b.Name = m.RecBy
WHERE c.ID = m.ID
However, as Anthony pointed out, you probably want to normalize out the strings in the RecBy column in the messages table, as you have the same data in the bases table.
From your description, it just sounds like you need two JOINS
SELECT TOP 1
c.SignalRec
FROM
config c
INNER JOIN
bases b
ON c.RecBy = b.NameNum
INNER JOIN
messages m
ON b.Name = m.RecBy
I think I might have not been clear enough what I wanted to do, sorry about that.
The data is actually different in the 2 tables, although the correlations are the same. It's kind of confusing to explain without going into detail about how the system works.
I actually found a very fast way of doing this.
Inside my sub-query I do this:
(SELECT TOP 1 config.Signal FROM config,bases
WHERE config.ID = messages.ID AND bases.Name = messages.RecBy AND bases.NameNum =
config.RecBy Order By...)
So this essentially compares the 2 RecBy's of different tables even though one is an integer and the other is a string. It reminds me of a match and look up in Excel.