Here is a brief explanation of what I'm trying to accomplish; my query follows below.
There are 4 tables and 1 view which are relevant for this particular query (sorry the names look messy, but they follow a strict convention that would make sense if you saw the full list):
Performances may have many Performers, and those associations are stored in PPerformer. Fans can have favorites, which are stored in Favorite_Performer. The _UpcomingPerformances view contains all the information needed to display a user-friendly list of upcoming performances.
My goal is to select all the data from _UpcomingPerformances, then include one additional column that specifies whether the given Performance has a Performer which the Fan added as their favorite. This involves selecting the list of Performers associated with the Performance, and also the list of Performers who are in Favorite_Performer for that Fan, and intersecting the two arrays to determine if anything is in common.
When I execute the below query, I get the error #1054 - Unknown column 'up.pID' in 'where clause'. I suspect it's somehow related to a misuse of Correlated Subqueries but as far as I can tell what I'm doing should work. It works when I replace up.pID (in the WHERE clause of t2) with a hard-coded number, and yes, pID is an existing column of _UpcomingPerformances.
Thanks for any help you can provide.
SELECT
up.*,
CASE
WHEN EXISTS (
SELECT * FROM (
SELECT RID FROM Favorite_Performer
WHERE FanID = 107
) t1
INNER JOIN
(
SELECT r.ID as RID
FROM PPerformer pr
JOIN Performer r ON r.ID = pr.Performer_ID
WHERE pr.Performance_ID = up.pID
) t2
ON t1.RID = t2.RID
)
THEN "yes"
ELSE "no"
END as pText
FROM
_UpcomingPerformances up
The problem is scope related. The nested Selects make the up table invisible inside the internal select. Try this:
SELECT
up.*,
CASE
WHEN EXISTS (
SELECT *
FROM Favorite_Performer fp
JOIN Performer r ON fp.RID = r.ID
JOIN PPerformer pr ON r.ID = pr.Performer_ID
WHERE fp.FanID = 107
AND pr.Performance_ID = up.pID
)
THEN 'yes'
ELSE 'no'
END as pText
FROM
_UpcomingPerformances up
Related
I'm trying to update the total revenue for offices located in different geographies. The geographies are defined by circles and polygons which are both in the shapes.shape column.
When I run the query below, MySQL throws "R_INVALID_GROUP_FUNC_USE: Invalid use of group function"
I tried to adapt this answer, but I can't figure out the logic with the conditional join and geospatial data -- it's not as simple as adding a subquery with a WHERE clause. (Or is it?)
For context, I have about 350 geographies and 150,000 offices.
UPDATE
shapes s
LEFT JOIN offices ON (
CASE
WHEN s.type = 'circle' THEN ST_Distance_Sphere(o.coords, s.shape) < s.radius
ELSE ST_CONTAINS(s.shape, o.coords)
END
)
SET
s.totalRevenue = SUM(o.revenue);
UPDATE:
This works, but it's slow and confusing. Is there a faster/more concise way?
UPDATE
shapes s
LEFT JOIN (
SELECT
t.shape_id,
SUM(g.revenue) revenue
FROM
shapes t
LEFT JOIN offices o ON (
CASE
WHEN t.type = 'circle' THEN ST_Distance_Sphere(o.coords, t.shape) < t.radius
ELSE ST_CONTAINS(t.shape, o.coords)
END
)
GROUP BY
t.shape_id
) b ON s.shape_id = b.shape_id
SET
s.totalRevenue = b.revenue;
I think that speed can be helped by splitting into two UPDATEs:
... WHERE t.type = 'circle'
AND ST_Distance_Sphere ...
and
... WHERE t.type != 'circle'
AND ST_CONCAINS ...
And then see if the resulting SQLs can be simplified.
To further investigate the query, please isolate the subquery b and see if the bulk of the time is in doing that SELECT (as opposed to the time doing the UPDATE).
Please provide SHOW CREATE TABLE for each table and EXPLAIN for both the UPDATE(s) and the isolated SELECT(s). A number of clues might come from such.
Overview
I have two tables as can be seen below:
user_planes
----------------------------------
|id |user_id|plane_id|fuel|status|
----------------------------------
| 2 1 1 1 Ready |
----------------------------------
shop_planes
------------------------
|id |name|fuel_capacity|
------------------------
| 1 bob 3 |
------------------------
Foreign Key Primary Key
user_planes.plane_id <-> shop_planes.id
I want to be able to get every field (SELECT *) in user_planes and name and fuel_capacity based on the following criteria:
WHERE user_planes.user_id = ? - Parameter which will be added to the query through PHP.
WHERE user_planes.status = 'Ready'
WHERE user_planes.fuel < shop_planes.fuel_capacity
The Issue and My Attempts
I've tried JOIN however it retrieves data which doesn't fit that criteria, meaning it gets extra data which is from shop_planes and not user_planes.
SELECT * FROM `user_planes` WHERE fuel IN (SELECT shop_planes.fuel_capacity FROM shop_planes WHERE fuel < shop_planes.fuel_capacity) AND user_planes.user_id = 1 AND status = 'Ready'
and
SELECT * FROM `user_planes` INNER JOIN `shop_planes` ON user_planes.fuel < shop_planes.fuel_capacity AND user_planes.user_id = 1 AND user_planes.status = 'Ready'
I've searched Stackoverflow and looked through many questions but I've not been able to figure it.
I've looked up many tutorials but still can't get the desired result.
The desired result is that the query should use the data stored in user_planes to retrieve data from shop_planes while at the same time not getting any excess data from shop_planes.
Disclaimer
I really struggle using JOIN queries, I could use multiple separate queries however I wish to optimise my queries hence I'm trying to bring it in to one query.
If their isn't clarity in the question, please do say, I'll update it to the best of my ability.
Note - Is there an easy query builder option available either through phpmyadmin or an alternative software?
Thanks in advance.
Your last attempt was not a bad one, the only thing you missed there was the join criteria you described at the beginning of your post. I also moved the other filters to the where clause to better distinguish between join condition and the filters.
SELECT `user_planes`.*
FROM `user_planes`
INNER JOIN `shop_planes` ON user_planes.plane_id = shop_planes.id
WHERE user_planes.fuel < shop_planes.fuel_capacity AND user_planes.user_id = 1 AND user_planes.status = 'Ready'
First you need the base JOIN
SELECT up.* -- only user_plane fields
FROM shop_planes sp -- CREATE alias for table or field
JOIN user_planes up
ON sp.id = up.plane_id
Case 1: apply a filter in where condition with php parameter.
SELECT up.*
FROM shop_planes sp
JOIN user_planes up
ON sp.id = up.plane_id
WHERE up.user_id = ?
Case 2: apply a filter in where condition with string constant
SELECT up.*
FROM shop_planes sp
JOIN user_planes up
ON sp.id = up.plane_id
WHERE user_planes.status = 'Ready'
Case 3: aply filter comparing fields from both tables
SELECT up.*
FROM shop_planes sp
JOIN user_planes up
ON sp.id = up.plane_id
WHERE up.fuel < sp.fuel_capacity
Try something like:
SELECT
up.id AS User_Plane_ID
, up.[user_id]
, up.plane_id
, up.fuel
, up.[status]
, sp.name AS shop_Plane_Name
, sp.fuel_capacity AS shop_Plane_Fuel_Capacity
FROM User_Planes up
INNER JOIN Shop_Planes sp ON up.plane_id = sp.id
AND up.fuel < sp.Fuel_Capacity
WHERE up.[status] = 'Ready'
AND up.[user_id] = ?
Definitely find a tutorial for JOINs, and don't use SELECT *. With SELECT *, you may end up querying much more than you actually need and it can cause problems if the table changes. You'll enjoy your day much more if you explicitly name the columns you want in your query.
I've aliased some of the columns (with AS) since some of those column names may be reserved words. I've also moved the JOIN criteria to include a filter on fuel
So, this query is currently used in a webshop to retrieve technical data about articles.
It has served its purpose fine except the amount of products shown have increased lately resulting in unacceptable long loading times for some categories.
For one of the worst pages this (and some other queries) get requested about 80 times.
I only recently learned that MySQL does not optimize sub-queries that don't have a depending parameter to only run once.
So if someone could help me with one of the queries and explain how you can replace the in's and exists's to joins, i will probably be able to change the other ones myself.
select distinct criteria.cri_id, des_texts.tex_text, article_criteria.acr_value, article_criteria.acr_kv_des_id
from article_criteria, designations, des_texts, criteria, articles
where article_criteria.acr_cri_id = criteria.cri_id
and article_criteria.acr_art_id = articles.art_id
and articles.art_deliverystatus = 1
and criteria.cri_des_id = designations.des_id
and designations.des_lng_id = 9
and designations.des_tex_id = des_texts.tex_id
and criteria.cri_id = 328
and article_criteria.acr_art_id IN (Select distinct link_art.la_art_id
from link_art, link_la_typ
where link_art.la_id = link_la_typ.lat_la_id
and link_la_typ.lat_typ_id = 17484
and link_art.la_ga_id IN (Select distinct link_ga_str.lgs_ga_id
from link_ga_str, search_tree
where link_ga_str.lgs_str_id = search_tree.str_id
and search_tree.str_type = 1
and search_tree.str_id = 10132
and EXISTS (Select *
from link_la_typ
where link_la_typ.lat_typ_id = 17484
and link_ga_str.lgs_ga_id = link_la_typ.lat_ga_id)))
order by article_criteria.acr_value
I think this one is the main badguy with sub-sub-sub-queries
I just noticed i can remove the last exist and still get the same results but with no increase in speed, not part of the question though ;) i'll figure out myself whether i still need that part.
Any help or pointers are appreciated, if i left out some useful information tell me as well.
I think this is equivalent:
SELECT DISTINCT c.cri_id, dt.tex_text, ac.acr_value, ac.acr_kv_des_id
FROM article_criteria AS ac
JOIN criteria AS c ON ac.acr_cri_id = c.cri_id
JOIN articles AS a ON ac.acr_art_id = a.art_id
JOIN designations AS d ON c.cri_des_id = d.des_id
JOIN des_texts AS dt ON dt.tex_id = d.des_tex_id
JOIN (SELECT distinct la.la_art_id
FROM link_art AS la
JOIN link_la_typ AS llt ON la.la_id = llt.lat_la_id
JOIN (SELECT DISTINCT lgs.lgs_ga_id
FROM link_ga_str AS lgs
JOIN search_tree AS st ON lgs.lgs_str_id = st.str_id
JOIN link_la_typ AS llt ON lgs.lgs_ga_id = llt.lat_ga_id
WHERE st.str_type = 1
AND st.str_id = 10132
AND llt.lat_typ_id = 17484) AS lgs
ON la.la_ga_id = lgs.lgs_ga_id
WHERE llt.lat_typ_id = 17484) AS la
ON ac.acr_art_id = la.la_art_id
WHERE a.art_deliverystatus = 1
AND d.des_lng_id = 9
AND c.cri_id = 328
ORDER BY ac.acr_value
All the IN <subquery> clauses can be replaced with JOIN <subquery>, where you then JOIN on the column being tested equaling the column returned by the subquery. And the EXISTS test is converted to a join with the table, moving the comparison in the subquery's WHERE clause into the ON clause of the JOIN.
It's probably possible to flatten the whole thing, instead of joining with subqueries. But I suspect performance will be poor, because this won't reduce the temporary tables using DISTINCT. So you'll get combinatorial explosion in the resulting cross product, which will then have to be reduced at the end with the DISTINCT at the top.
I've converted all the implicit joins to ANSI JOIN clauses, to make the structure clearer, and added table aliases to make things more readable.
In general, you can convert a FROM tab1 WHERE ... val IN (SELECT blah) to a join like this.
FROM tab1
JOIN (
SELECT tab1_id
FROM tab2
JOIN tab3 ON whatever = whatever
WHERE whatever
) AS sub1 ON tab1.id = sub1.tab1_id
The JOIN (an inner join) will drop the rows that don't match the ON condition from your query.
If your tab1_id values can come up duplicate from your inner query, use SELECT DISTINCT. But don't use SELECT DISTINCT unless you need to; it is costly to evaluate.
I know this has been asked plenty times before, but I cant find an answer that is close to mine.
I have the following query:
SELECT c.cases_ID, c.cases_status, c.cases_title, ci.custinfo_FName, ci.custinfo_LName, c.cases_timestamp, o.organisation_name
FROM db_cases c, db_custinfo ci, db_organisation o
WHERE c.userInfo_ID = ci.userinfo_ID AND c.cases_status = '2'
AND organisation_name = (
SELECT organisation_name
FROM db_sites s, db_cases c
WHERE organisation_ID = '111'
)
AND s.sites_site_ID = c.sites_site_ID)
What I am trying to do is is get the cases, where the sites_site_ID which is defined in the cases, also appears in the db_sites sites table alongside its organisation_ID which I want to filter by as defined by "organisation_ID = '111'" but I am getting the response from MySQL as stated in the question.
I hope this makes sense, and I would appreciate any help on this one.
Thanks.
As the error states your subquery returns more then one row which it cannot do in this situation. If this is not expect results you really should investigate why this occurs. But if you know this will happen and want only the first result use LIMIT 1 to limit the results to one row.
SELECT organisation_name
FROM db_sites s, db_cases c
WHERE organisation_ID = '111'
LIMIT 1
Well the problem is, obviously, that your subquery returns more than one row which is invalid when using it as a scalar subquery such as with the = operator in the WHERE clause.
Instead you could do an inner join on the subquery which would filter your results to only rows that matched the ON clause. This will get you all rows that match, even if there is more than one returned in the subquery.
UPDATE:
You're likely getting more than one row from your subquery because you're doing a cross join on the db_sites and db_cases table. You're using the old-style join syntax and then not qualifying any predicate to join the tables on in the WHERE clause. Using this old style of joining tables is not recommended for this very reason. It would be better if you explicitly stated what kind of join it was and how the tables should be joined.
Good pages on joins:
http://dev.mysql.com/doc/refman/5.0/en/join.html (for the right syntax)
http://www.codinghorror.com/blog/2007/10/a-visual-explanation-of-sql-joins.html (for the differences between the types of joins)
I was battling this for an hour, and overcomplicated it completely. Sometimes a quick break and writing it out on an online forum can solve it for you ;)
Here is the query as it should be.
SELECT c.cases_ID, c.cases_status, c.cases_title, ci.custinfo_FName, ci.custinfo_LName, c.cases_timestamp, c.sites_site_ID
FROM db_cases c, db_custinfo ci, db_sites s
WHERE c.userInfo_ID = ci.userinfo_ID AND c.cases_status = '2' AND (s.organisation_ID = '111' AND s.sites_site_ID = c.sites_site_ID)
Let me re-write what you have post:
SELECT
c.cases_ID, c.cases_status, c.cases_title, ci.custinfo_FName, ci.custinfo_LName,
c.cases_timestamp, c.sites_site_ID
FROM
db_cases c
JOIN
db_custinfo ci ON c.userInfo_ID = ci.userinfo_ID and c.cases_status = '2'
JOIN
db_sites s ON s.sites_site_ID = c.sites_site_ID and s.organization_ID = 111
dont blame for the database design.I am not its database architect. I am the one who has to use it in current situation
I hope this will be understandable.
I have 3 tables containing following data with no foreign key relationship b/w them:
groups
groupId groupName
1 Admin
2 Editor
3 Subscriber
preveleges
groupId roles
1 1,2
2 2,3
3 1
roles
roleId roleTitle
1 add
2 edit
Query:
SELECT roles
from groups
LEFT JOIN preveleges ON (groups.groupId=preveleges.groupId)
returns specific result i.e roles.
Problem: I wanted to show roleTitle instead of roles in the above query.
I am confused how to relate table roles with this query and returns required result
I know it is feasible with coding but i want in SQL.Any suggestion will be appreciated.
SELECT g.groupName,
GROUP_CONCAT(r.roleTitle
ORDER BY FIND_IN_SET(r.roleId, p.roles))
AS RoleTitles
FROM groups AS g
LEFT JOIN preveleges AS p
ON g.groupId = p.groupId
LEFT JOIN roles AS r
ON FIND_IN_SET(r.roleId, p.roles)
GROUP BY g.groupName ;
Tested at: SQL-FIDDLE
I would change the data structure it self. Since It's not normalised, there are multiple elements in a single column.
But it is possible with SQL, if for some (valid) reason you can't change the DB.
A simple "static" solution:
SELECT REPLACE(REPLACE(roles, '1', 'add'), '2', 'edit') from groups
LEFT JOIN preveleges ON(groups.groupId=preveleges.groupId)
A more complex but still ugly solution:
CREATE FUNCTION ReplaceRoleIDWithName (#StringIds VARCHAR(50))
RETURNS VARCHAR(50)
AS
BEGIN
DECLARE #RoleNames VARCHAR(50)
SET #RoleNames = #StringIds
SELECT #RoleNames = REPLACE(#RoleNames, CAST(RoleId AS VARCHAR(50)), roleTitle)
FROM roles
RETURN #RoleNames
END
And then use the function in the query
SELECT ReplaceRoleIDWithName(roles) from groups
LEFT JOIN preveleges ON(groups.groupId=preveleges.groupId)
It is possible without function, but this is more readable. Made without editor so it's not tested in anyway.
You also tagged the question with PostgreSQL and it's actually quite easy with Postgres to work around this broken design:
SELECT grp.groupname, r.roletitle
FROM groups grp
join (
select groupid, cast(regexp_split_to_table(roles, ',') as integer) as role_id
from privileges
) as privs on privs.groupid = grp.groupid
join roles r on r.roleid = privs.role_id;
SQLFiddle: http://sqlfiddle.com/#!12/5e87b/1
(Note that I changed the incorrectly spelled name preveleges to the correct spelling privileges)
But you should really, really re-design your data model!
Fixing your design also enables you to define foreign key constraints and validate the input. In your current model, the application would probably break (just as my query would), if someone inserted the value 'one,two,three' into the roles table.
Edit
To complete the picture, using Postgres's array handling the above could be slightly simplified using a similar approach as MySQL's find_in_set()
select grp.groupname, r.roletitle
from groups grp
join privileges privs on grp.groupid = privs.groupid
join roles r on r.roleid::text = any (string_to_array(privs.roles, ','))
In both cases if all role titles should be shown as a comma separated list, the string_agg() function could be used (which is equivalent to MySQL's group_concat()
select grp.groupname, string_agg(r.roletitle, ',')
from groups grp
join privileges privs on grp.groupid = privs.groupid
join roles r on r.roleid::text = any (string_to_array(privs.roles, ','))
group by grp.groupname