I would like to get one value instead of all values when they have the same name.
within an sql query. Im using fullcalendar. and have two tables one for the events(evenement) and one for the receiver(evenementontvanger).
evenementontvanger:
id idEvent
1 231
2 231
3 231
evenement:
id title
231 hello
I would like to show only one title not 3
my sql query:
"SELECT
*
FROM
`evenement`
JOIN
`evenementontvanger` ON `evenementontvanger`.`idEvent` = `evenement`.`id`
WHERE
`idEvent` = `evenement`.`id`"
You can use distinct to do so as
SELECT distinct `evenementontvanger`.`idEvent`,`evenement`.`title`
FROM
`evenement`
JOIN
`evenementontvanger` ON `evenementontvanger`.`idEvent` = `evenement`.`id`
WHERE
`idEvent` = `evenement`.`id`;
How ever the above will not bother about idWerknemer and if you want to display them as group use Group_concat as
SELECT `evenementontvanger`.`idEvent`,
`evenement`.`title`,
group_concat(`evenementontvanger`.`idWerknemer`) as `idWerknemer`
FROM
`evenement`
JOIN
`evenementontvanger` ON `evenementontvanger`.`idEvent` = `evenement`.`id`
WHERE
`idEvent` = `evenement`.`id`
Group By `evenementontvanger`.`idEvent`
Check the demo here http://sqlfiddle.com/#!2/290b4/13
Use SELECT DISTINCT on your query to eliminate duplicates :
The ALL and DISTINCT options specify whether duplicate rows should be
returned. ALL (the default) specifies that all matching rows should be
returned, including duplicates. DISTINCT specifies removal of
duplicate rows from the result set. It is an error to specify both
options. DISTINCTROW is a synonym for DISTINCT.
From MySQL docs
use either top 1
OR
select distinct
Related
I want make a leaderboard from my database, I already make a code but the sql says error
"SET #a1 = (SELECT SUM(d.poin_diskusi)
FROM diskusi d
GROUP BY d.id_akun)
MySQL said: Documentation
#1242 - Subquery returns more than 1 row"
heres my sql query :
SET #a1 = (SELECT SUM(d.poin_diskusi)
FROM diskusi d
GROUP BY d.id_akun);
SET #a2 = (SELECT SUM(j.nilai_jawaban)
FROM jawaban j
GROUP BY j.id_akun);
SET #hasil = #a1 + #a2;
SELECT #hasil
Thank you !
this is an example data in table jawaban:
this is an example data in table diskusi:
and my desired answer:
where tera123 have 135 TOTAL(d.poin_diskusi+j.nilai_jawaban) and david123 have 90 TOTAL(d.poin_diskusi+j.nilai_jawaban)
the point is to show TOTAL for every user
It looks to me (without looking at your images; if you want to show information, please provide it in text) like you want something like:
select id_akun, sum(point_value) as total_points from (
select id_akun, sum(poin_diskusi) as point_value
from diskusi group by id_akun
union all
select id_akun, sum(nilai_jawaban) as point_value
from jawaban group by id_akun
) as point_values
group by id_akun
The problem are the GROUP BY keywords. Inside the images you provided with example data, one can see that there are multiple entries for the columns jawaban.id_akun and diskusi.id_akun. Because of that, both SELECT will return multiple rows as result, for each different value of the id columns one summed up row. Try it without the GROUP BY clause.
I have two tables first and second.
first Table:
ID NAME ADDRESS
1 test testing address
2 test1 testing address
3 test2 testing address
4 test3 testing address
second Table:
T_ID Partner_id date
1 2 12345678
3 4 32164584
If input T_id is given. Then corresponding Partner_id is taken and it is compared with the ID from first table and corresponding row should be selected.
Can you please tell me.
In php I can write this with two queries but I want it to be in a single query.
Queries in php:
$q=mysqli_query($conn, "SELECT Partner_id from second where T_ID=1");
$qa=mysqli_fetch_array($q);
$w=mysqli_query($conn, "SELECT * from first where ID=$qa[0]");
But, how to combine this two statements?
The specified result can be returned using a query with a join operation.
SELECT f.*
FROM first f
JOIN second s
ON s.Partner_id = f.ID
WHERE s.T_ID=1
Note that there is a potential for this to return more rows that the original, if the first query returns more than one row. (That is, we don't assume that T_ID is unique in second, or that every row with a given T_ID value will have identical values for Partner_id.)
There are other query patterns that will return an equivalent result, but the join operation is the normative pattern.
try to use union ,see this this link
where The SQL UNION operator combines the result of two or more SELECT statements.
SELECT * FROM first WHERE ID IN( SELECT Parent_id FROM second WHERE T_ID = 1 )
or
SELECT * FROM first WHERE ID = ( SELECT Parent_id FROM second WHERE T_ID = 1 )
SELECT * FORM first_table AS f
JOIN second_table AS s
ON s.parent_id =f.id
WHERE s.T_ID = $id
I have a database with 2 tables. one called "object" and the other called "object_meta".
now i want to save additional fields depending to an entry in the "object" table inside the "object_meta" table. until now i do so with 2 queries.
1st query:
SELECT * FROM object WHERE id=$id
and the 2nd query:
SELECT * FROM object_meta WHERE object_id=$id
and then i put this 2nd query inside a new field of the 1st array called ex: meta_fields
including the array of the query to "object_meta"
$array[$id]['additional_fields'][$add_field[key]] = $add_field[value];
please can someone show me how to do this with a join?
thx a lot :D
SELECT object.*, object_meta.*
FROM object
INNER JOIN object_meta
ON object.id = object_meta.object_id
WHERE object.id = ?
Adjust the INNER JOIN to a LEFT JOIN if object_meta does not carry information for every object. The fields of object_meta will then be NULL if there is no matching row.
Note that this will not put the values into addtional_fields, but on the same level as all the other values.
This is how you can do it, however I would suggest to select only the required fields from both tables which you want to display and you can do as table_name.col_name1,table_name.col_name2 etc and can use where condition on first table col name with the input value.
select * from `object`
inner join `object_meta` on `object_meta`.`object_id` = `object`.`id`
How can I select the next result just by specifying the name?
I have a table that looks like this, no IDs, just list of usernames.
row1 = username(Alex)
row2 = username(Bob)
row3 = username(Britney)
row4 = username(Steve)
row5 = username(Courtney)
row6 = username(Greg)
row7 = username(Abul)
row8 = username(Roger)
row9 = username(Victoria)
row10 = username(Brooke)
Let's say, I want to select all Items after 'Greg'. How can I achieve this?
No, there is no inherent ordering of tables in SQL, so there is no way (other than by alphabetical order) to determine which name comes next.
In fact, the order displayed in the question is entirely arbitrary - without a specified order by clause, retrieval order of rows is essentially random.
this can be done by two query..first find the id of the particular name.
like select id from tablename where username='Greg'
then fetching that id,
select * from tablename where id>fetching id.
Add ID column to your table, and then use LIMIT as offset
SELECT * FROM users LIMIT (SELECT ID FROM username WHERE username='Greg'), MAX(ID)
Didn't tested, but you can play with it
I have a reviews table that contains three ways to rate an item. The items themselves then have three columns to hold the average for each value respectively.
I could do this using three nested queries in an update query, but I feel like this is inefficient... Is there a way to update them all at once?
So far I've used this as my select query:
SELECT AVG(rating_1),AVG(rating_2),AVG(rating_3) FROM items_reviews WHERE item_id = 1
I just don't know how to use the result of that query to update an item row.
You could use an join in the UPDATE:
UPDATE items a
INNER JOIN
(
SELECT
item_id,
AVG(rating_1) AS avg1,
AVG(rating_2) AS avg2,
AVG(rating_3) AS avg3
FROM items_reviews
WHERE item_id = 1
GROUP BY item_id
) b ON a.item_id = b.item_id
SET
a.avgrating1 = b.avg1,
a.avgrating2 = b.avg2,
a.avgrating3 = b.avg3