I have 3 tables (candidates, candidate_notes and candidate_events)
CANDIDATES | CANDIDATE_NOTES | CANDIDATE_EVENTS
id | id | id
name | candidate_event_id | type
surname | candidate_id
city | note
...
One candidate can have many notes.
One note has one kind of event.
I would like to obtain all the candidates that have notes of kind of event 1 but only that.
For example, if the candidate 1 have 5 notes, one of type 1, other 3 of type 3 and another one of type 6, I don't want to see it in the results.
Can someone help me with this query?
Thanks
One method uses group by and having:
select cn.candidate_id
from candidate_notes cn join
candidate_events e
on cn.candidate_event_id = e.candidate_event_id
group by cn.candidate_id
having min(type) = 1 and min(type) = max(type);
Related
I have two columns displaying the same type of information but not necessarily the same data. Although some of the data overlaps each column may/may not contain information that will also include NULL values. Like so:
Company ID | Company Name | Company ID | Company Name
-----------+--------------+------------+-------------
1 | A | 1 | A
2 | B | NULL | NULL
NULL | NULL | 3 | C
I am trying to merge columns 1 and 2 to columns 3 and 4, respectively, so that I have two columns that look like this:
Company ID | Company Name
-----------+-------------
1 | A
2 | B
3 | C
Looking at similar stackoverflow questions, I have doubt this may be done easily. Is this possible? Please, let me know!
Anything helps.
As you don't seem to be around to answer questions for clarification right now, let's go ahead.
It seems, you do actually have the four columns in question in a single table - but than, there should be no duplicate column names. Once they are unique, the following should work:
UPDATE SomeTable
SET company_ID_1 = IFNULL(company_ID_1, company_ID_2)
, company_Name_1 = IFNULL(company_Name_1, company_Name_2)
WHERE
company_ID_1 IS NULL
OR
company_Name_1 IS NULL
;
If the presented is actually the output of a join, you could replace the same by:
SELECT
IFNULL(SomeTable1.company_ID, SomeTable2.company_ID) company_ID
, IFNULL(SomeTable1.company_Name, SomeTable2.company_Name) company_Name
FROM SomeTable1
LEFT JOIN SomeTable2
ON SomeTable1.company_ID = SomeTable2.company_ID
UNION ALL
SELECT
IFNULL(SomeTable1.company_ID, SomeTable2.company_ID) company_ID
, IFNULL(SomeTable1.company_Name, SomeTable2.company_Name) company_Name
FROM SomeTable1
RIGHT JOIN SomeTable2
ON SomeTable1.company_ID = SomeTable2.company_ID
WHERE SomeTable1.company_ID IS NULL
ORDER BY company_ID
;
See it in action: SQL Fiddle
Please comment, if and as this requires adjustment / further detail.
I asked a similar question earlier today, but I've run into another issue that I need assistance with.
I have a logging system that scans a server and catalogs every user that's online at that given moment. Here is how my table looks like:
-----------------
| ab_logs |
-----------------
| id |
| scan_id |
| found_user |
-----------------
id is an autoincrementing primary key. Has no real value other than that.
scan_id is an integer that is incremented after each successful scan of all users. It so I can separate results from different scans.
found_user. Stores which user was found online during the scan.
The above will generate a table that could look like this:
id | scan_id | found_user
----------------------------
1 | 1 | Nick
2 | 2 | Nick
3 | 2 | John
4 | 3 | John
So on the first scan the system found only Nick online. On the 2nd it found both Nick and John. On the 3rd only John was still online.
My problem is that I want to get the total amount of unique users connected to the server at the time of each scan. In other words, I want the aggregate number of users that have connected at each scan. Think counter.
From the example above, the result I want from the sql is:
1
2
2
EDIT:
This is what I have tried so far, but it's wrong:
SELECT COUNT(DISTINCT(found_user)) FROM ab_logs WHERE DATE(timestamp) = CURDATE() GROUP BY scan_id
What I tried returns this:
1
2
1
The code below should give you the results you are looking for
select s.scan_id, count(*) from
(select distinct
t.scan_id
,t1.found_user
from
tblScans t
inner join tblScans t1 on t.scan_id >= t1.scan_id) s
group by
s.scan_id;
Here is sqlFiddle
It assumes the names are unique and includes current and every previous scans in the count
Try with group by clause:
SELECT scan_id, count(*)
FROM mytable
GROUP BY scan_id
For some reason, I am unable to export a table of subscribers from my phpList (ver. 3.0.6) admin pages. I've searched on the web, and several others have had this problem but no workarounds have been posted. As a workaround, I would like to query the mySQL database directly to retrieve a similar table of subscribers. But I need help with the SQL command. Note that I don't want to export or backup the mySQL database, I want to query it in the same way that the "export subscribers" button is supposed to do in the phpList admin pages.
In brief, I have two tables to query. The first table, user contains an ID and email for every subscriber. For example:
id | email
1 | e1#gmail.com
2 | e2#gmail.com
The second table, user_attribute contains a userid, attributeid, and value. Note in the example below that userid 1 has values for all three possible attributes, while userid's 2 and 3 are either missing one or more of the three attributeid's, or have blank values for some.
userid | attributeid | value
1 | 1 | 1
1 | 2 | 4
1 | 3 | 6
2 | 1 | 3
2 | 3 |
3 | 1 | 4
I would like to execute a SQL statement that would produce a row of output for each id/email that would look like this (using id 3 as an example):
id | email | attribute1 | attribute2 | attribute3
3 | e3#gmail.com | 4 | "" | "" |
Can someone suggest SQL query language that could accomplish this task?
A related query I would like to run is to find all id/email that do not have a value for attribute3. In the example above, this would be id's 2 and 3. Note that id 3 does not even have a blank value for attributeid3, it is simply missing.
Any help would be appreciated.
John
I know this is a very old post, but I just had to do the same thing. Here's the query I used. Note that you'll need to modify the query based on the custom attributes you have setup. You can see I had name, city and state as shown in the AS clauses below. You'll need to map those to the attribute id. Also, the state has a table of state names that I linked to. I excluded blacklisted (unsubscribed), more than 2 bounces and unconfirmed users.
SELECT
users.email,
(SELECT value
FROM `phplist_user_user_attribute` attrs
WHERE
attrs.userid = users.id and
attributeid=1
) AS name,
(SELECT value
FROM `phplist_user_user_attribute` attrs
WHERE
attrs.userid = users.id and
attributeid=3
) AS city,
(SELECT st.name
FROM `phplist_user_user_attribute` attrs
LEFT JOIN `phplist_listattr_state` st
ON attrs.value = st.id
WHERE
attrs.userid = users.id and
attributeid=4
) AS state
FROM
`phplist_user_user` users
WHERE
users.blacklisted=0 and
users.bouncecount<3 and
users.confirmed=1
;
I hope someone finds this helpful.
I apologise in advance if this might seem simple as my assignment needs to be passed in 3 hours time and I don't have enough time to do some further research as I have another pending assignment to be submitted tonight. I only know the basic MYSQL commands and not these types. Please help.
Say that I have two tables:
________________ _________________
| customers | | agents |
|________________| |_________________|
|(pk)customer id | |(pk) agent_id |
|(fk) agent_id | | first_name |
| first_name | | last_name |
| last_name | | address |
|________________| |_________________|
Basically I would just like to know how to query something like: (in incorrect terms)
SELECT * FROM customers WHERE agent_id = '(agent_id of Michael Smith from the AGENTS table)'
obviously I only have the agent_id of the agent and i can directly call it if i know what the agents name is based on the id like:
SELECT * FROM customers WHERE agent_id = '4'
but how can i query it by submitting the agent first name and last name as parameter?
(first name and last name because agents can have the same names, or even same last names)
Remember your foreign key does not help you building the query, you have to tell the database what you want in the query (however, a foreign key can help data spread across tables more consistent).
You can use a JOIN here.
You can implement it like this:
SELECT *
FROM customers C
INNER JOIN agents A ON C.agent_id = A.agent_id
WHERE A.last_name = 'Smith'
AND A.first_name = 'Michael';
You can do it without a join as well.
select *
from customers
where customers.agent_id in (
select agents.agent_id
from agents
where agents.first_name = 'Michael' and agents.last_name = 'Smith'
);
I have a little SQL but I can't find the way to get back text just numbers. - revised!
SELECT if( `linktype` = "group",
(SELECT contactgroups.grname
FROM contactgroups, groupmembers
WHERE contactgroups.id = groupmembers.id ???
AND contactgroups.id = groupmembers.link_id),
(SELECT contactmain.contact_sur
FROM contactmain, groupmembers
WHERE contactmain.id = groupmembers.id ???
AND contactmain.id = groupmembers.link_id) ) AS adat
FROM groupmembers;
As now I have improved a bit gives back some info but ??? (thanks to minitech) indicate my problem. I can't see how could I fix... Any advice welcomed! Thansk
Contactmain (id, contact_sur, email2)
data:
1 | Peter | email#email.com
2 | Andrew| email2#email.com
Contactgroups (id, grname)
data:
1 | All
2 | Trustee
3 | Comitee
Groupmembers (id, group_id, linktype, link_id)
data:
1 | 1 | contact | 1
2 | 1 | contact | 2
3 | 2 | contact | 1
4 | 3 | group | 2
And I would like to list out who is in the 'Comitee' the result should be Andrew and Trustee if I am right:)
It does look a bit redundant on the join since you are implying both the ID and Link_ID columns are the same value. Since BOTH select values are derived from a qualification to the group members table, I have restructured the query to use THAT as the primary table and do a LEFT JOIN to each of the other tables, anticipating from your query that the link should be found from ONE or the OTHER tables. So, with each respective LEFT JOIN, you will go through the GroupMembers table only ONCE. Now, your IF(). Since the group members is the basis, and we have BOTH tables available and linked, we just grab the column from one table vs the other respectively. I've included the "linktype" too just for reference purposes. By using the STRAIGHT_JOIN will help the engine from trying to change the interpretation of how to join the tables.
SELECT STRAIGHT_JOIN
gm.linktype,
if( gm.linktype = "group", cg.grname, cm.contact_sur ) ADat
from
groupmembers gm
left join contactgroups cg
ON gm.link_id = cg.id
left join contactmain cm
ON gm.link_id = cm.id
If contactgroups.id must equal groupmembers.id but must also equal 2, that's redundant and also probably where your problem is. It works fine as you've written it: http://ideone.com/7EGLZ so without knowing what it's actually supposed to do I can't help more.
EDIT: I'm unfamiliar with the comma-separated FROM, but it gives the same result since you don't select anything from the other table so it doesn't really matter.