I'm a bit embarassed asking this here, but here goes:
I've got two tables, which you can see here:
http://img411.imageshack.us/img411/4562/query.jpg
I need to copy the effortid from the one table into the other, making sure that the values still maintain the correction relationships. The primary key for each is a combination of loggerid & datetime. What's the best way to do this?
Thanks in advance, and don't make fun :)
Change it to an Update Query instead. The joins should function correctly, but will not add missing rows. To do that, you would use an Append Query, like you have setup, but with a left join and a check for nulls. The sample below updates the LogID table with information residing in LogSiteID table.
Append Missing Records from Logger Site ID to LogID
INSERT INTO logID ( [Datetime], loggerid, temp, effortid )
SELECT ls.datetime, ls.loggerid, ls.temp, ls.effortid
FROM logID AS l RIGHT JOIN [Logger Site ID] AS ls ON (l.temp = ls.temp) AND (l.loggerid = ls.loggerid) AND (l.Datetime = ls.datetime)
WHERE (((l.loggerid) Is Null));
Update effortids from Logger Site ID to LogID
UPDATE logID AS l INNER JOIN [Logger Site ID] AS ls ON (l.Datetime = ls.datetime) AND (l.temp = ls.temp) AND (l.loggerid = ls.loggerid) SET l.effortid = [ls].[effortid];
Related
I'm working with mySQL db and trying to display the correct data for the user. In order to do that I check if the data that I call from one backend is equal to username from another backend like so
SELECT * FROM db1 WHERE db1.table.value = db2.table.value
Names of databases are A and B.
SELECT *
FROM `A.onboardings`
, `B.loginsystem`
WHERE onboardings.sales_email = loginsystem.username
The problem is I get an error A.A.onboardings doesn't exists and A.B.loginsystem doesn't exist pls help :(
You must use this form - from A onboardings
You have to put the backticks in the right pace, or else mysql things your table is called A.onboardings
As seen bleow the needs to be around the database and the table name
And the use of aliases helps to keep even in big queries a good overview and yu have to write less
"SELECT * FROM `A`.`onboardings` a1,`B`.`loginsystem` b1 WHERE a1.sales_email = b1.username"
Try this one( Change the query according to your DB name, table, and matching column name)
SELECT * FROM mydatabase1.tblUsers INNER JOIN mydatabase2.tblUsers ON mydatabase1.tblUsers.UserID = mydatabase2.tblUsers.UserID
The problem is that
`A.onboardings`
is not the same as
A.onboardings
The first is a table reference where there table name has a period in it. The second is for the onboardings table in database A.
In addition, you should be using JOIN!!!
SELECT *
FROM A.onboardings o JOIN
B.loginsystem ls
ON o.sales_email = ls.username;
If you feel compelled to escape the identifies -- which I do not recommend -- then:
SELECT *
FROM `A`.`onboardings` o JOIN
`B`.`loginsystem` ls
ON o.sales_email = ls.username;
So i'm trying to select unread messages with a query, but the results are blank. I need to get the info from a seperate table read so it will know it was read or not. Im trying to do something like a IF statement so if readed not exists it will be unread, but i can't get it fixed
this is my query:
SELECT * FROM notify
INNER JOIN readed ON readed.acc_ID = '26' AND readed.user_ID = '6'
AND readed.msg_ID = notify.ID AND readed.readed != '1' OR readed.ID IS NULL
WHERE notify.groep = '1'
DB - readed
ID - int
user_ID - int
acc_ID - int
msg_ID - int
readed - enum ('0','1')
DB - notify
ID - int
notfi - text
thumb_src - text
title - text
url - text
groep - int
I hope someone know whats the problem!
The query seems correct to me, except the part with the OR, so I suppose that the problem is with the data. I will first try to show how you could improve the query nevertheless, and then try to show how to debug your data.
First, let's leave away the OR condition since this won't work as expected in a JOIN ON clause.
Second, when comparing integer fields to values, you should not put quotes around the values. This will only worry every person who tries to understand the query because the quotes denote string values, and it will worry (i.e. slow down) MySQL's parser, because it must convert the string values to numbers.
Third, mixing up normal WHERE conditions and JOIN ON conditions is worrying and bad style (IMHO). I always recommend to put only the conditions which actually link the tables into the JOIN ON clause, and other conditions elsewhere.
Following this advice would lead to something like that:
SELECT * FROM
notify INNER JOIN readed ON
readed.msg_ID = notify.ID
WHERE
readed.acc_ID = 26 AND
readed.user_ID = 6 AND
readed.readed != '1' AND
notify.groep = 1
This should do the same as your original query minus the OR part.
Now, since we suspect that there is a problem with the data, we can begin to debug the data. First, leave away the WHERE clause:
SELECT * FROM
notify INNER JOIN readed ON
readed.msg_ID = notify.ID
If this returns data, then you at least know that there are rows in the readed table matching rows in the notify table. If it does not return any data, then there are no rows which fit together, and have found the root of your problem.
Provided that the above returns data, re-add the WHERE clause line by line and test after each step. For example, start with
SELECT * FROM
notify INNER JOIN readed ON
readed.msg_ID = notify.ID
WHERE
readed.acc_ID = 26 AND
and continue with
SELECT * FROM
notify INNER JOIN readed ON
readed.msg_ID = notify.ID
WHERE
readed.acc_ID = 26 AND
readed.user_ID = 6 AND
and so on, testing the query each time.
That way, you hopefully will find out where the problem is. I am convinced that the problem is with the data, not with the query.
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.
I have two tables and both include 2 columns, sureness and kindness and and they are related to each other by dataitemID and id. Just to show you the structure I will put 2 selects that I got from database:
SELECT ID,sureness,kindness FROM omid.tweet ;
SELECT ID,DataitemID,sureness,kindness FROM omid.entity_epoch_data ;
and I want to copy all value of sureness and kindness in omid.tweet into entity_epoch_data where entity_epoch_data.entityID is equal to entityID coming from entity_relation where tweet.ID =entity_relation.ID
I want just to do it in mysql rather than reading the whole table in java and updating the database in the loop but I am so confused. How can I do that?I appreciate any help:)
Update:
I wrote the code as follow but it does not work:
update tweet, entity_epoch_data
set entity_epoch_data.sureness= tweet.sureness,
entity_epoch_data.kindness = tweet.kindness ,
entity_epoch_data.calmness = tweet.calmness ,
entity_epoch_data.happiness = tweet.happiness
WHERE entity_epoch_data.EntityID in(
SELECT EntityID FROM omid.entity_dataitem_relation
INNER JOIN omid.tweet t ON entity_dataitem_relation.DataitemID = t.ID)
It's actually pretty straight forward. The UPDATE clause works like a JOIN and then use SET to set the values
UPDATE tweet INNER JOIN entity_epoch_data
ON tweet.id = entity_epoch_data.id
SET entity_epoch_data.sureness= tweet.sureness,
entity_epoch_data.kindness = tweet.kindness
I realized that i was using a varchar attribute as a index/key in a query, and that is killing my query performance. I am trying to look in my precienct table and get the integer ID, and then update my record in the household table with the new int FK, placed in a new column. this is the sql i have written thus far. but i am getting a
Error 1093 You can't specify target table 'voterfile_household' for update in FROM clause, and i am not sure how to fix it.
UPDATE voterfile_household
SET
PrecID = (SELECT voterfile_precienct.ID
FROM voterfile_precienct INNER JOIN voterfile_household
WHERE voterfile_precienct.PREC_ID = voterfile_household.Precnum);
Try:
update voterfile_household h, voterfile_precienct p
set h.PrecID = p.ID
where p.PREC_ID = h.Precnum
Take a look at update reference here.
Similarly, you can use inner join syntax as well.
update voterfile_household h inner join voterfile_precienct p on (h.Precnum = p.PREC_id)
set h.PrecID = p.ID
What if the subquery returns more than one result? That's why it doesn't work.
On SQL Server you can get this type of thing to work if the subquery does "SELECT TOP 1 ...", not sure if mysql will also accept it if you add a "limit 1" to the subquery.
I also think this is pretty much a duplicate of this question ("Can I have an inner SELECT inside of an SQL UPDATE?") from earlier today.
Firstly, your index on a varchar isn't always a bad thing, if it is not a key you can shrink how much of the field you index to only index say the first 10 chars or so.
Secondly, it won't let you do this as if it is a set that is returned it could break.