I have three table one is for users and other one is for subject and third one contain user_id, subject_id foreign keys.
I get unknow coloumn when I run the following sql.
SELECT wp_cons_users.first_name, wp_cons_subject.subject, wp_cons_skilllist.skill_level
FROM `wp_cons_subject`
JOIN wp_cons_skilllist ON wp_cons_skilllist.user_id = wp_cons_users.id
JOIN wp_cons_users ON wp_cons_users.id = wp_cons_skilllist.user_id
WHERE wp_cons_subject.id = '1'
ORDER BY `wp_cons_skilllist`.`skill_level` DESC
I can't find the error with this query.
wp_cons_skilllist
column link to
id (primay)
user_id wp_cons_users -> id
subj_id wp_cons_subject -> id
skill_level
Here I try to get the username, skill level and subject for any given subject id.
Looks like your main problem is with the ordering of your JOINs. In your first join, you are matching with wp_cons_users.id, but you don't join that table until later in the query. If you re-order the joins it should work better. Also, based on your table description, it seems that you will also need to join on subject_id. This query should help:
SELECT wp_cons_users.first_name
, wp_cons_subject.subject
, wp_cons_skilllist.skill_level
FROM wp_cons_users
JOIN `wp_cons_subject`
ON wp_cons_users.id=`wp_cons_subject`.user_id
AND wp_cons_subject.id = '1'
JOIN
wp_cons_skilllist
ON wp_cons_skilllist.user_id = wp_cons_users.id
AND wp_cons_skilllist.subject_id = `wp_cons_subject`.id
ORDER BY `wp_cons_skilllist`.`skill_level` DESC
I am guessing about the field names that weren't in your original query, so you may have to make some changes if they're different from what I'm assuming.
Without information about your attributes in your table, I'm afraid we can only assume that there is no ID column in your wp_cons_users table.
when I corrected the query to following it started to work.
SELECT wp_cons_users.first_name, wp_cons_subject.subject, wp_cons_skilllist.skill_level
FROM `wp_cons_skilllist`
JOIN wp_cons_subject ON wp_cons_subject.id = wp_cons_skilllist.subject_id
JOIN wp_cons_users ON wp_cons_users.id = wp_cons_skilllist.user_id
WHERE wp_cons_skilllist.subject_id = '1'
ORDER BY `wp_cons_skilllist`.`skill_level` DESC
LIMIT 0 , 30
Related
Please help me to write correct query for a few tables. I need to replace all id here from another table
api json
I am trying to make query like this
SELECT incident.`number`, `user`.first_name, (SELECT `user`.first_name from ITSM.`user` JOIN incident on `user`.sys_id = incident.id_created_by) as createdby
from ITSM.incident
JOIN ITSM.`user` on incident.id_caller = `user`.sys_id
;*
but it doesn#t work, I got an error: Subquery returns more than 1 row
How can i make a right query?
This one doesn't work also, same error:
SELECT incident.`number`, (SELECT user.first_name from ITSM.`user`, ITSM.incident WHERE user.sys_id = incident.id_created_by) as createdby
from ITSM.incident
JOIN ITSM.`user` on incident.id_caller = user.sys_id*
;
and this is my
DB id for user who created
You don't need a subquery. Just refer to the source table of each column in the select clause, here if you need 2 joins to the same table give these an alias and refer to the columns using that alias.
SELECT incident.`number`
, caller.first_name as caller_name
, creator.first_name AS createdby
FROM ITSM.incident
JOIN ITSM.`user` AS caller ON incident.id_caller = caller.sys_id
JOIN ITSM.`user` AS creator ON incident.id_created_by = creator.sys_id
Nb. I'm assuming your join logic is correct
Im trying to do a select query on a table along with an inner join afterwards to link data from the owner to the cats
the ownercat is using a foreign key on the id linking to the ownerinfo id
USE CATTERY;
SELECT
OWNERINFO.ID, OWNERINFO.First_Name, OWNERINFO.Last_Name, OWNERINFO.Phone, OWNERINFO.AddrL1, OWNERINFO.AddrL2, OWNERINFO.AddrL3, OWNERINFO.PostCode,
GROUP_CONCAT(DISTINCT OWNERCAT.Chip_ID)
FROM OWNERINFO
INNER JOIN OWNERCAT ON OWNERINFO.ID = OWNERCAT.ID
WHERE ID = 1;
I get returned the following error:
Error Code: 1052. Column 'ID' in where clause is ambiguous 0.0014 sec
removing the concat distinct statement still produces the same error, im not sure how to get around this issue
You need to define from which table the ID on WHERE-clause come from (you can use aliases). Secondly, as you are using GROUP_CONCAT, you should have GROUP BY in the query:
SELECT
oi.ID,
oi.First_Name,
oi.Last_Name,
oi.Phone,
oi.AddrL1,
oi.AddrL2,
oi.AddrL3,
oi.PostCode,
GROUP_CONCAT(DISTINCT oc.Chip_ID)
FROM OWNERINFO oi
INNER JOIN OWNERCAT oc ON oc.ID=oi.ID
WHERE oi.ID = 1
GROUP BY oi.ID
The problem is in the WHERE clause: ID is ambiguous, because that column is available in both tables.
You may think that, since you are joining the tables on ID, the database is able to tell that it has the same value, but that's not actually the case.
So just qualify the column in the WHERE clause, ie change this:
WHERE ID = 1
To either:
WHERE OWNERINFO.ID = 1
Or the equivalent:
WHERE OWNERCAT.ID = 1
Also please note that your query uses GROUP_CONCAT(), which is an aggregate function. This implies that you need a GROUP BY clause, that should list all non-aggregated column (ie all columns other than the one that is within GROUP_CONCAT()).
What's wrong with this query, im selecting data from 3 different tables here. First title of exam from "class_exams" table , second selecting sum of total marks from "results" table. Query works fine without where clause.
SELECT id, exam_date , (
SELECT title
FROM class_exams
WHERE result_heads.exam_id = class_exams.id
) AS exam_title, (
SELECT sum( marks )
FROM results
WHERE result_heads.id = results.head_id
) AS obt_marks
FROM `result_heads` WHERE exam_title = 'test';
Error comes
Unknown column 'exam_title' in 'where clause'
Consider using Join
If I understand the table schema , it should be like this :
SELECT result_heads.id, result_heads.exam_date , sum( results.marks )AS obt_marks
FROM results JOIN result_heads
ON results.exam_id = result_heads.id
GROUP BY result_heads.id, result_heads.exam_date
I think you need to add the name of table in where clouse
WHERE `tbl_name`.`exam_title = 'test';
I know this is an old post, but I like to fill the answers where old posts end to prevent dead end posting. It looks like the table name is not being called out in the From clause
See this link http://www.techonthenet.com/mysql/where.php and look at the example - Joining Tables.
Database: MySql 5.5.3
I have a type column in table topic, if the type is 'E' which means there is an entry exist in 'Event' Table and it should query "TOPIC_HAS_EVENT" table to get few more colums from the EVENT Table. In the same way if Type is 'P' which means there is an entry exist in 'Poll Table' and it should query "TOPIC_HAS_POLL" table to get few columns from POLL Table. If the type is null then it should query as usual to get all the rows and their comments from the comment table.
The end results should have all the topics rows of all types ('E','P', NULL) and their specific columns from other table. If that can accomplish easily then i need to add few more columns as mentioned below
More complex
If type='E' have some rows, it should get some more rows such as user information from EVENT_HAS_USER table.
Relationship
Each Topic has Many Comments
Each Topic has One Event
Each Topic has One Poll
EVENT ManyTOMany User
Query so far created. I still need to add 'type' column. Please help me with it.
SELECT DISTINCT
T.TOPIC_GUID, COUNT(*) TOTAL_COMMENTS
FROM
CIRCLE C, CIRCLE_HAS_USER CHU, CIRCLE_HAS_TOPIC CHT, TOPIC T
LEFT JOIN TOPIC_COMMENT TC ON T.TOPIC_GUID = TC.TOPIC_GUID
WHERE
CHT.CIRCLE_GUID = C.CIRCLE_GUID
AND T.TOPIC_GUID < 400000 -- ?
AND CHT.TOPIC_GUID = T.TOPIC_GUID
AND CHU.CIRCLE_GUID = C.CIRCLE_GUID
AND CHU.USER_GUID = 1
AND CHU.STATUS = 'A'
GROUP BY T.TOPIC_GUID
ORDER BY T.LAST_UPDATED_TIMESTAMP DESC
LIMIT 10
Try this:
select (case when type = 'type1' then (select field from table1) else (select field from table2) end) as a from table;
I have the following query, which lists all accounts with matching facebook accounts- the issue is that sometimes there is more than one row in the facebook table that matches the join and then we have duplicate rows being repeated being returned even though ac.id AS id should be the unique primary key.
SELECT ac.id AS id
, ac.first_name
, ac.last_name
, ac.email
, ac.company_name
, upd8r_facebook_accts.id AS fb
FROM upd8r_user_accts ac
LEFT OUTER JOIN upd8r_facebook_accts
ON ac.id = upd8r_facebook_accts.user_id
WHERE ac.`rfid` = ''
AND ac.last_name != ''
AND ac.`owner_id` = '121'
ORDER BY ac.`last_name` ASC
Two issues are duplicate rows being returned (i think its when there is more than one row in the facebook table matching the upd8r_user_accts.id. And the query takes 10 seconds to run... i have an index on upd8r_user_accts.id thinking this might help, but it hasn't
tip:
make index on columns which comes with ON or WHERE
change SELECT by SELECT STRAIGHT JOIN
Since upd8r_user_accts.id is the primary key - adding an index onto this column will not help matters and is superfluous.
The results of your query indicate some users have multiple facebook accounts.
You don't state the datatype if the id column(s) but you could try something like this..
SELECT ac.id AS id, ac.first_name, ac.last_name, ac.email, ac.company_name, upd8r_facebook_accts.id AS fb
FROM upd8r_user_accts ac
LEFT OUTER JOIN upd8r_facebook_accts ON ac.id = upd8r_facebook_accts.user_id
WHERE ac.`rfid` = ''
AND ac.last_name != ''
AND ac.`owner_id` = '121'
AND upd8r_facebook_accts.id = (SELECT MAX(ufa.id) FROM upd8r_facebook_accts ufa WHERE ufa.user_id = ac.id)
ORDER BY ac.`last_name` ASC
This would have the effect of displaying only one row per user but bear in mind the rows it removes might not be the ones you wanted to be removed from your results.
It also assumes you can do a MAX function on the Id column.