I'm trying to write a MYSQL Query that updates a cell in table1 with information gathered from 2 other tables;
The gathering of data from the other 2 tables goes without much issues (it is slow, but that's because one of the 2 tables has 4601537 records in it.. (because all the rows for one report are split in a separate record, meaning that 1 report has more than 200 records)).
The Query that I use to Join the two tables together is:
# First Table, containing Report_ID's: RE
# Table that has to be updated: REGI
# Join Table: JT
SELECT JT.report_id as ReportID, REGI.Serienummer as SerialNo FROM Blancco_Registration.TrialTable as REGI
JOIN (SELECT RE.Value_string, RE.report_id
FROM Blancco_new.mc_report_Entry as RE
WHERE RE.path_id=92) AS JT ON JT.Value_string = REGI.Serienummer
WHERE REGI.HardwareType="PC" AND REGI.BlanccoReport=0 LIMIT 100
This returns 100 records (I limit it because the database is in use during work hours and I don't want to steal all resources).
However, I want to use these results in a Query that updates the REGI table (which it uses to select the 100 records in the first place).
However, I get the error that I cannot select from the table itself while updateing it (logically). So I tried selecting the select statement above into a temp table and than Update it; however, then I get the issue that I get to much results (logically! I only need 1 result and get 100) however, I'm getting stuck in my own thougts.. I ultimately need to fill the ReportID into each record of REGI.
I know it should be possible, but I'm no expert in MySQL.. is there anybody that can point me into the right direction?
Ps. fixing the table containing 400k records is not an option, it's a program from an external developer and I can only read that database.
The errors I'm talking about are as follows:
Error Code: 1093. You can't specify target table 'TrialTable' for update in FROM clause
When I use:
UPDATE TrialTable SET TrialTable.BlanccoReport =
(SELECT JT.report_id as ReportID, REGI.Serienummer as SerialNo FROM Blancco_Registration.TrialTable as REGI
JOIN (SELECT RE.Value_string, RE.report_id
FROM Blancco_new.mc_report_Entry as RE
WHERE RE.path_id=92) AS JT ON JT.Value_string = REGI.Serienummer
WHERE REGI.HardwareType="PC" AND REGI.BlanccoReport=0 LIMIT 100)
WHERE TrialTable.HardwareType="PC" AND TrialTable.BlanccoReport=0)
Then I tried:
UPDATE TrialTable SET TrialTable.BlanccoReport = (SELECT ReportID FROM (<<and the rest of the SQL>>> ) as x WHERE X.SerialNo = TrialTable.Serienummer)
but that gave me the following error:
Error Code: 1242. Subquery returns more than 1 row
Haveing the Query above with a LIMIT 1, gives everything the same result
Firstly, your query seems to be functionally identical to the following:
SELECT RE.report_id ReportID
, REGI.Serienummer SerialNo
FROM Blancco_Registration.TrialTable REGI
JOIN Blancco_new.mc_report_Entry RE
ON RE.Value_string = REGI.Serinummer
WHERE REGI.HardwareType = "PC"
AND REGI.BlanccoReport=0
AND RE.path_id=92
LIMIT 100
So, why not use that?
EDIT:
I still don't get it. I can't see what part of the problem the following fails to solve...
UPDATE TrialTable REGI
JOIN Blancco_new.mc_report_Entry RE
ON RE.Value_string = REGI.Serinummer
SET TrialTable.BlanccoReport = RE.report_id
WHERE REGI.HardwareType = "PC"
AND REGI.BlanccoReport=0
AND RE.path_id=92;
(This is not an answer, but maybe a pointer towards a few points that need further attention)
Your JT sub query looks suspicious to me:
(SELECT RE.Value_string, RE.report_id
FROM Blancco_new.mc_report_Entry as RE
WHERE RE.path_id=92
GROUP BY RE.report_id)
You use group by but don't actually use any aggregate functions. The column RE.Value_string should strictly be something like MAX(RE.Value_string) instead.
Related
I'm working on an update statement but I keep getting this error. Anyone have any advice on how to fix it. I've tried looking at solutions from similar questions for the past hour but can't seem to get them to work. Here's my sql statemtent:
UPDATE T_SUBSCRIBERS
SET FULLNAME=
(SELECT CONCAT (T_REGISTERED_FNAME, T_REGISTERED_LNAME) FROM T_REGISTERED WHERE
T_REGISTERED_UID = T_SUBSCRIBERS.T_SUBSCRIBERS_UID);
** Update ur sql like this :**
UPDATE T_SUBSCRIBERS
SET FULLNAME=
(SELECT CONCAT (T_REGISTERED_FNAME, T_REGISTERED_LNAME) FROM T_REGISTERED WHERE
T_REGISTERED_UID = T_SUBSCRIBERS.T_SUBSCRIBERS_UID AND ROWNUM = 1);
You have more more rows that match the conditions than you expect.
You can find the offending rows by doing:
select T_REGISTERED_UID, count(*)
from T_REGISTERED
group by T_REGISTERED_UID
having count(*) > 1;
If you just want a quick-and-dirty solution, use limit:
UPDATE T_SUBSCRIBERS s
SET FULLNAME = (SELECT CONCAT(T_REGISTERED_FNAME, T_REGISTERED_LNAME)
FROM T_REGISTERED r
WHERE r.T_REGISTERED_UID = s.T_SUBSCRIBERS_UID
LIMIT 1
);
In general, though, it is best not repeat column values like this in different tables. When you want the full name, just join to T_REGISTERED. After all, what happens if the user updates their registration name?
I have table "Temp" and table "Today", with same column names ("url" and "date").
I want to update "date" column of "Temp" table when url match.
But my tables are quite big (30K elements) and phpmyadmin does not want to execute the following - right - query :
update Temp Tp
inner join Today Ty on
Tp.url = Ty.url
set Tp.date = Ty.date
I get a "Query execution was interrupted, error #1317"
Why ? I expect this is because I pay for a mutualized server (OVH) and I am not able to execute queries longer than 2-3 seconds.
Anyway, now I want to execute this query range by range. First 1000 rows, 1000-2000 etc.
I tried the following :
update Temp Tp
inner join
(
select Tp2.date
from Temp Tp2
inner join Today Ty2
on Tp2.url = Ty2.url
limit 1000
) Ty on Tp.url = Ty.url
set Tp.date = Ty.date
BUT I get the following error : #1054 - Unknown column 'Ty.url' in 'on clause'
I couldn't find out why ?
As far as I can see, there are two problems here. First, as already mentioned by #pmbAustin, you're missing a column in your subquery.
Secondly, I think your subquery should be selecting the date from Ty2, rather than Tp2:
update Temp Tp
inner join
(
select Ty2.date, Tp2.url
from Temp Tp2
inner join Today Ty2
on Tp2.url = Ty2.url
limit 1000
) Ty on Tp.url = Ty.url
set Tp.date = Ty.date
See SQLFiddle (although for practical reasons, this demo is limited to 2).
Although you haven't specifically asked this (and you're probably aware already), for completeness it should be mentioned that for subsequent queries, LIMIT should be used alongside OFFSET (or just use the shortcut LIMIT 1000, 1000, LIMIT 2000,1000, LIMIT <offset>, <limit>, etc.
I've got a select statement that returns a list of all items in a document store that have comments (stored in a separate comments table).
What I'm trying to do is to update the value of another column in public_document_store (skin_id) for all the documents that have released comments, based on the statement below.
This returns the records I want to update:
SELECT public_document_store_talkback.document_id,
public_document_store.section_id
FROM public_document_store
INNER JOIN public_document_store_talkback ON public_document_store_talkback.document_id = public_document_store.document_id
WHERE public_document_store_talkback.is_released = 1
AND public_document_store_talkback.is_rejected = 0
AND public_document_store.section_id = 10;
I've tried to update the skin_id field like this:
Update public_document_store SET skin_id = 6
WHERE document_id IN (Select... [as per the statement above] )
But this returns an error:
[Err] 1241 - Operand should contain 1 column(s)
I've tried various other permutations based on other answers here, but without any luck (My knowledge of SQL is pretty basic, so apologies if I am missing something obvious here)
Any ideas how I can make this work would be much appreciated.
Your SELECT query needs only a little modification to convert it into an UPDATE statement,
UPDATE public_document_store a
INNER JOIN public_document_store_talkback b
ON b.document_id = a.document_id
SET a.skin_id = 6
WHERE b.is_released = 1 AND
b.is_rejected = 0 AND
a.section_id = 10
I am bit stuck with this one.. what i want is update app_name (first table). It returns no error.. but does nothing...
UPDATE tbl_m_app AS tma, tbl_measure AS tm
SET tma.app_name='Ap1'
WHERE (tm.mesure_id = tma.mesure_id
AND tm.live = 1)
This query will do the same work in more obvious way and without joins
UPDATE tbl_m_app AS tma
SET tma.app_name='Ap1'
WHERE tma.mesure_id IN (SELECT tm.mesure_id FROM tbl_measure AS tm WHERE tm.live = 1)
I think this SQL is fine, it's just not matching any rows.
Check this by using a select with the same where clause:
SELECT * FROM tbl_measure tm WHERE tm.live=1;
0 rows returned, right?
I have two separate SELECT statements:
SELECT VCe.VId FROM `VCe` WHERE `YId` = 9007 AND `MaId` =76 AND `MoId` = 2851
SELECT r_pts.p_id FROM r_pts WHERE r_pts.v_id IN (57202, 57203, 69597, 82261, 82260, 69596, 69595, 82259)
When they are run separately they both complete in under .05sec however when I nest the first one within the second, it dramatically increases to 3.3sec.
I would like to do a join so that I can get the output from the second SELECT using the first select as the result set for the IN() but I cannot figure out how to include WHERE conditions in a JOIN.
Edit: Also what is the correct syntax to do a join as I am requesting?
Thanks for your help, its appreciated!
Equivalent to MattMcKnight's query whilst illustrating "how to include WHERE conditions in a JOIN":
SELECT r.p_id
FROM r_pts r
INNER JOIN VCe v
ON v.VId = r.v_id
AND
v.YId = 9007
AND
v.MaId = 76
AND
v.MoId = 2851
SELECT r_pts.p_id FROM r_pts, 'VCe' WHERE r_pts.v_id = VCe.VId AND VCe.YId = 9007 AND VCe.MaId =76 AND VCe.MoId = 2851
The basic goal of a join is to describe how the two tables relate. I inferred from your example that the v_id column in the r_pts table was a foreign key pointing to the VId primary key in the VCe table. When you add a term in the query (such as "r_pts.v_id = VCe.VId") that has a field from each table you wish to join, that tells the database how to match up the rows between the tables to make "virtual rows" that contain the columns from both tables. Your other query terms limit which rows are included in the result set.