Let me explain what I mean with that question:
Lets say I have to tables like these:
customers
id customer location
1 Adam UK
2 Pete US
values
id value
1 10
1 7
2 3
2 41
Let's ignore here for a moment that that (and the following query) wouldn't make a lot of sense. It's meant as a simplified example.
Now, if I run this query
SELECT id, customer, value FROM customers INNER JOIN values GROUP BY id
I should get this result (distinct by id)
id customer value
1 Adam 10
2 Pete 3
What I would like to be able to do is get that to use it in a search result list, but for actual displaying of the results I'd like to do something like this:
Customer: Adam
Values: 10, 7
So, basically, while I need to have a result set that's distinct for the ID, I'd still like to somehow save the rows dropped by the GROUP BY to show the values list like above. What is the best way to do this?
Look at http://mysql.com/group_concat - which only will work in MySql.
Better link: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html#function_group-concat
Technically, the following is not valid SQL even though MySQL allows it:
Select customers.id, customers.customer, values.value
From customers
Inner Join values
On values.id = customers.id
Group By customers.id
The SQL spec requires that every column in the Select clause be referenced in the Group By or in an aggregate function. However, given what you said later in your post, what I think you want is GROUP_CONCAT as first mentioned by Erik (+1) which is a function specific to MySQL:
Select customers.customer, Group_Concat(values.value)
From customers
Inner Join values
On values.id = customers.id
Group By customers.customer
Related
Let me explain a little bit about what I am trying to do because I dont even know the vocab to use to ask. I have an Access 2016 database that records staff QA data. When a staff member misses a QA we assign a job aid that explains the process and they can optionally send back a worksheet showing they learned about what was missed. If they do all of these ina 3 month period they get a credit on their QA score. So I have a series of records all of whom have a date we assigned the work(RA1) and MAY have a work returned date(RC1).
In the below image "lavalleer" has earned the credit because both of her sheets got returned. "maduncn" Did not earn the credit because he didn't do one.
I want to create a query that returns to me only the people that are like "lavalleer". I tried hitting google and searched here and access.programmers.co.uk but I'm only coming up with instructions to use Not null statements. That wouldn't work for me because if I did a IS Not Null on "maduncn" I would get the 4 records but it would exclude the null.
What I need to do is build a query where I can see staff that have dates in ALL of their RC1 fields. If any of their RC1 fields are blank I dont want them to return.
Consider:
SELECT * FROM tablename WHERE NOT UserLogin IN (SELECT UserLogin FROM tablename WHERE RCI IS NULL);
You could use a not exists clause with a correlated subquery, e.g.
select t.* from YourTable t where not exists
(select 1 from YourTable u where t.userlogin = u.userlogin and u.rc1 is null)
Here, select 1 is used purely for optimisation - we don't care what the query returns, just that it has records (or doesn't have records).
Or, you could use a left join to exclude those users for which there is a null rc1 record, e.g.:
select t.* from YourTable t left join
(select u.userlogin from YourTable u where u.rc1 is null) v on t.userlogin = v.userlogin
where v.userlogin is null
In all of the above, change all occurrences of YourTable to the name of your table.
Currently have a single table with large amount of data in access, due to the size I couldn't easily work with it in Excel any more.
I'm partially there on a query to pull data from this table.
7 Column table
One column GL_GL_NUM contains a transaction number. ~ 75% of these numbers are pairs. I'm trying to pull the records (all columns information) for each unique transaction number in this column.
I have put together some code from googling that hypothetically should work but I think I'm missing something on the syntax or simply asking access to do what it cannot.
See below:
SELECT SOURCE_FUND, GLType, Contract, Status, Debit, Credit, GL_GL_NUM
FROM Suspense
JOIN (
SELECT TC_TXN_NUM TXN_NUM, COUNT(GL_GL_NUM) GL_NUM
FROM Suspense
GROUP BY TC_TXN_NUM HAVING COUNT(GL_GL_NUM) > 1 ) SUB ON GL_GL_NUM = GL_NUM
Hey Beth is this the suggested code? It says there is a syntax error in the FROM clause. Thanks.
SELECT * from SuspenseGL
JOIN (
SELECT TC_TXN_NUM, COUNT(GL_GL_NUM) GL_NUM
FROM Suspense
GROUP BY TC_TXN_NUM
HAVING COUNT(GL_GL_NUM) > 1
Do you want detailed results (all rows and columns) or aggregate results, with one row per tx number?
If you want an aggregate result, like the count of distinct transaction numbers, then you need to apply one or more aggregate functions to any other columns you include.
If you run
SELECT TC_TXN_NUM, COUNT(GL_GL_NUM) GL_NUM
FROM Suspense
GROUP BY TC_TXN_NUM
HAVING COUNT(GL_GL_NUM) > 1
you'll get one row for each distinct txn, but if you then join those results back with your original table, you'll have the same number of rows as if you didn't join them with distinct txns at all.
Is there a column you don't want included in your results? If not, then the only query you need to work with is
select * from suspense
Considering your column names, what you may want is:
SELECT SOURCE_FUND, GLType, Contract, Status, sum(Debit) as sum_debit,
sum(Credit) as sum_credit, count(*) as txCount
FROM Suspense
group by
SOURCE_FUND, GLType, Contract, Status
based on your comments, if you can't work with aggregate results, you need to work with them all:
Select * from suspense
What's not working? It doesn't matter if 75% of the txns are duplicates, you need to send out every column in every row.
OK, let's say
Select * from suspense
returns 8 rows, and
select GL_GL_NUM from suspense group by GL_GL_NUM
returns 5 rows, because 3 of them have duplicate GL_GL_NUMs and 2 of them don't.
How many rows do you want in your result set? if you want less than 8 rows back, you need to perform some sort of aggregate function on each column you want returned.
You could do something like the following:
SELECT S.* FROM
SUSPENSE AS S
INNER JOIN (SELECT DISTINCT GL_GL_NUM, MIN(ID) AS ID FROM SUSPENSE
GROUP BY GL_GL_NUM) AS S2
ON S.ID = S2.ID
AND S.GL_GL_NUM = S2.GL_GL_NUM
Which would return a single row for a unique gl_gl_num. However if the other rows have different data it will not be shown. You would have to either aggregate that data up using SUM(Credit), SUM(Debit) and then GROUP BY the gl_gl_num.
I have attached a SQL Fiddle to demonstrate my results and make this clearer.
http://sqlfiddle.com/#!3/8284f/2
fiId is a primary key of Table1. Why does this query return as many rows as there are fiId in table1. The fiId is being limited to 1 row in the where clause. The query performs properly when a group by Table1.fiId is added, surely this should not be needed? Thanks.
SELECT
Table1.fiId,
SUM(CASE Table2.type IN (4,7) THEN Table2.valueToSum ELSE 0 END),
FROM
Table1 INNER JOIN Table3 ON Table1.fiId = Table3.parentId
INNER JOIN Table2 ON Table2.leId = Table3.fiId
WHERE
Table1.fiId = 76813 AND
Table2.insId = 431144
When using aggregate functions in your SELECT such as SUM and COUNT when selecting other columns as well, a GROUP BY including those additional columns is required. While I don't know the exact reason behind this, it definitely helps to put the results in context.
Consider the following query:
SELECT Name, Count(Product) as NumOrders
FROM CustomerOrders
GROUP BY Name
Here, we assume that we will get results like this:
Name NumOrders
------------------
Joe 15
Sally 5
Jim 23
Now, if SQL did not require the GROUP BY, then what would you expect the output to be? My best guess would be something like this:
Name NumOrders
------------------
Joe 43
Sally 43
Jim 43
In that case, while there may in fact be 43 order records in the table, including Name doesn't really provide any useful data. Instead, we just have a bunch of names out of context.
For more on this, see a similar question here: Why do I need to explicitly specify all columns in a SQL "GROUP BY" clause - why not "GROUP BY *"?
I am now creating a reporting service with visual business intelligent.
i try to count how many users have been created under an org_id.
but the report consist of multiple org_id. and i have difficulties on counting how many has been created under that particular org_id.
TBL_USER
USER_ID
0001122
0001234
ABC9999
DEF4545
DEF7676
TBL_ORG
ORG_ID
000
ABC
DEF
EXPECTED OUTPUT
TBL_RESULT
USER_CREATED
000 - 2
ABC - 1
DEF - 2
in my understanding, i need nested SELECT, but so far i have come to nothing.
SELECT COUNT(TBL_USER.USER_ID) AS Expr1
FROM TBL_USER INNER JOIN TBL_ORG
WHERE TBL_USER.USER_ID LIKE 'TBL_ORG.ORG_ID%')
this is totally wrong. but i hope it might give us clue.
It looks like the USER_ID value is the concatenation of your ORG_ID and something to make it unique. I'm assuming this is from a COTS product and nothing a human would have built.
Your desire is to find out how many entries there are by department. In SQL, when you read the word by in a requirement, that implies grouping. The action you want to take is to get a count and the reserved word for that is COUNT. Unless you need something out of the TBL_ORG, I see no need to join to it
SELECT
LEFT(T.USER_ID, 3) AS USER_CREATED
, COUNT(1) AS GroupCount
FROM
TBL_USER AS T
GROUP BY
LEFT(T.USER_ID, 3)
Anything that isn't in an aggregate (COUNT, SUM, AVG, etc) must be in your GROUP BY.
SQLFiddle
I updated the fiddle to also show how you could link to TBL_ORG if you need an element from the row in that table.
-- Need to have the friendly name for an org
-- Now we need to do the join
SELECT
LEFT(T.USER_ID, 3) AS USER_CREATED
, O.SOMETHING_ELSE
, COUNT(1) AS GroupCount
FROM
TBL_USER AS T
-- inner join assumes there will always be a match
INNER JOIN
TBL_ORG AS O
-- Using a function on a column is a performance killer
ON O.ORG_ID = LEFT(T.USER_ID, 3)
GROUP BY
LEFT(T.USER_ID, 3)
, O.SOMETHING_ELSE;
I am having a slow brain day...
The tables I am joining:
Policy_Office:
PolicyNumber OfficeCode
1 A
2 B
3 C
4 D
5 A
Office_Info:
OfficeCode AgentCode OfficeName
A 123 Acme
A 456 Acme
A 789 Acme
B 111 Ace
B 222 Ace
B 333 Ace
... ... ....
I want to perform a search to return all policies that are affiliated with an office name. For example, if I search for "Acme", I should get two policies: 1 & 5.
My current query looks like this:
SELECT
*
FROM
Policy_Office P
INNER JOIN Office_Info O ON P.OfficeCode = O.OfficeCode
WHERE
O.OfficeName = 'Acme'
But this query returns multiple rows, which I know is because there are multiple matches from the second table.
How do I write the query to only return two rows?
SELECT DISTINCT a.PolicyNumber
FROM Policy_Office a
INNER JOIN Office_Info b
ON a.OfficeCode = b.OfficeCode
WHERE b.officeName = 'Acme'
SQLFiddle Demo
To further gain more knowledge about joins, kindly visit the link below:
Visual Representation of SQL Joins
Simple join returns the Cartesian multiplication of the two sets and you have 2 A in the first table and 3 A in the second table and you probably get 6 results. If you want only the policy number then you should do a distinct on it.
(using MS-Sqlserver)
I know this thread is 10 years old, but I don't like distinct (in my head it means that the engine gathers all possible data, computes every selected row in each record into a hash and adds it to a tree ordered by that hash; I may be wrong, but it seems inefficient).
Instead, I use CTE and the function row_number(). The solution may very well be a much slower approach, but it's pretty, easy to maintain and I like it:
Given is a person and a telephone table tied together with a foreign key (in the telephone table). This construct means that a person can have more numbers, but I only want the first, so that each person only appears one time in the result set (I ought to be able concatenate multiple telephone numbers into one string (pivot, I think), but that's another issue).
; -- don't forget this one!
with telephonenumbers
as
(
select [id]
, [person_id]
, [number]
, row_number() over (partition by [person_id] order by [activestart] desc) as rowno
from [dbo].[telephone]
where ([activeuntil] is null or [activeuntil] > getdate()
)
select p.[id]
,p.[name]
,t.[number]
from [dbo].[person] p
left join telephonenumbers t on t.person_id = p.id
and t.rowno = 1
This does the trick (in fact the last line does), and the syntax is readable and easy to expand. The example is simple but when creating large scripts that joins tables left and right (literally), it is difficult to avoid that the result contains unwanted duplets - and difficult to identify which tables creates them. CTE works great for me.