I have a table with multiple data for same ID. I want to get the first row data for the ID.
I have added the below SQL that I have tried.
SELECT
"client"."id",
"client"."company_name",
"client_details"."address"
from Client
LEFT OUTER JOIN "client_details" ON ("client"."id" = "client_details"."client_id")
Since I have multiple address for the same ID, can we get only the first id?
Currently the output I get is 2 rows with different addresses.
You can add to your SQL LIMIT 1 and in case you want to be sure the order you can also add to your SQL ORDER BY...
You can use distinct on:
select distinct on (c.id) c.id, c.company_name, cd.address
from Client c left join
client_details cd
on c.id = cd.client_id
order by c.id, ?;
The ? is for the column that specifies the ordering (the definition of "first"). I am guessing that cd.id is what you want.
Note that this query removes the double quotes and introduces table aliases. This is easier on both the eyes (to read) and the fingers (to type).
use row_number()
select * from
(
SELECT
"client"."id",
"client"."company_name",
"client_details"."address",row_number() over(partition by "client"."id" order by "client_details"."address") as rn
from Client
LEFT OUTER JOIN "client_details" ON "client"."id" = "client_details"."client_id"
)A where rn=1
If there is a field you can order the results by you could use a lateral join e.g.
SELECT
"client"."id",
"client"."company_name",
"client_details"."address"
from Client
left join lateral (
select *
from client_details cd
where cd.client_id = client.id
order by [some_ordering_field]
limit 1
) "client_details" on true
Related
i have following sql in java project:
select distinct * from drivers inner join licenses on drivers.user_id=licenses.issuer_id
inner join users on drivers.user_id=users.id
where (licenses.state='ISSUED' or drivers.status='WAITING')
and users.is_deleted=false
And result i database looks like this:
And i would like to get only one result instead of two duplicated results.
How can i do that?
Solution 1 - That's Because one of data has duplicate value write distinct keyword with only column you want like this
Select distinct id, distinct creation_date, distinct modification_date from
YourTable
Solution 2 - apply distinct only on ID and once you get id you can get all data using in query
select * from yourtable where id in (select distinct id from drivers inner join
licenses
on drivers.user_id=licenses.issuer_id
inner join users on drivers.user_id=users.id
where (licenses.state='ISSUED' or drivers.status='WAITING')
and users.is_deleted=false )
Enum fields name on select, using COALESCE for fields which value is null.
usually you dont query distinct with * (all columns), because it means if one column has the same value but the rest isn't, it will be treated as a different rows. so you have to distinct only the column you want to, then get the data
I suspect that you want left joins like this:
select *
from users u left join
drivers d
on d.user_id = u.id and d.status = 'WAITING' left join
licenses l
on d.user_id = l.issuer_id and l.state = 'ISSUED'
where u.is_deleted = false and
(d.user_id is not null or l.issuer_id is not null);
I'm trying to do a left join. But I only want the first row of the joined table.
When I do :
SELECT DISTINCT
c.reference
FROM contracts as c
output : 7400 rows
But when I try to do the left join I have a lot of duplicates.
I already tried to only get the first row but it does not work. Here is my code :
SELECT DISTINCT
c.reference,
contract_premiums.start_date
FROM contracts as c
LEFT OUTER JOIN contract_premiums ON contract_premiums.contract_id=(
SELECT contract_id FROM contract_premiums
WHERE contract_premiums.contract_id = c.id
ORDER BY contract_premiums.created_at ASC
LIMIT 1)
output : 11500 rows
Note the database in Postgresql and I'm using this request in klipfolio.
If you just want the latest start_date per reference, you can use aggregation:
select c.reference, max(cp.start_date) max_start_date
from contracts c
left join contracts_premiums cp on cp.contract_id = c.id
group by c.reference
This guarantees that you will only get one row per reference.
If you want more columns from contracts_premiums, or if you want to sort by a column other than start_date (possibly, you want created_at instead), then another option is distinct on:
select distinct on (c.reference) c.reference, cp.start_date, cp.created_at
from contracts c
left join contracts_premiums cp on cp.contract_id = c.cid
order by c.reference, cp.created_at desc
Is there anyway to join two tables on multiple potential conditions?
I'm currently migrating some code from Postgres to Bigquery where I joined on multiple potential values like:
SELECT
*
FROM
(
SELECT
offer_table.offer_id
,customer_table.customer_name
,customer_table.visit_count
,ROW_NUMBER() OVER (PARTITION BY offer_table.offer_id ORDER BY customer_table.visit_count DESC) AS customer_visit_rank
FROM
offer_table
LEFT JOIN customer_table ON
(
offer_table.customer_id = customer_table.customer_id
OR offer_table.email = customer_table.email
OR offer_table.phone = customer_table.phone
)
) dummy
WHERE
customer_visit_rank = 1
I needed to this because my offer and customer data had inconsistent usage of our id, email, and phone fields but all were valid potential matches. If multiple fields worked (ex: id and email matched), there would be duplicate rows and I'd filter them out based on the row_number column after ranking using the ORDER BY section.
However when I try to join on multiple conditions in BigQuery, I get this error message:
LEFT OUTER JOIN cannot be used without a condition that is an equality of fields from both sides of the join.
Has anyone figured out a solution to join on multiple values instead of doing the above?
You can write separate queries, then use COALESCE:
SELECT
*
FROM
(
SELECT
offer_table.offer_id
,COALESCE(c1.customer_name,c2.customer_name,c3.customer_name)
,COALESCE(c1.visit_count,c2.visit_count,c3.visit_count)
,ROW_NUMBER() OVER (PARTITION BY offer_table.offer_id ORDER BY customer_table.visit_count DESC) AS customer_visit_rank
FROM
offer_table
LEFT JOIN customer_table c1
ON offer_table.customer_id = customer_table.customer_id
LEFT JOIN customer_table c2
ON offer_table.email = customer_table.email
LEFT JOIN customer_table c3
ON offer_table.phone = customer_table.phone
)
) AS dummy
WHERE
customer_visit_rank = 1
This query feeds a data table with sorting, filtering, and pagination. All features worked fine until I added the INNER JOIN and then i got:
The multi-part 'identifier "Types.Description" could not be bound
if i remove the second WHERE clause at the end of the query the LIKE statements work, but i lose pagination. I removed some of the LIKE clauses to try and clean up this monstrous query.
SELECT *
FROM (
SELECT ROW_NUMBER() OVER (ORDER BY TAG asc) AS RowNumber, *
FROM (
SELECT (SELECT COUNT(*) FROM Instruments) AS TotalDisplayRows, (SELECT COUNT(*) FROM Instruments) AS TotalRows, Instruments.Tag, Instruments.Location, Instruments.Description, Types.Description As TypeDesc, Manufacturer.Name, Lease.Name as LeaseName, Facility.Name as FacName
FROM Instruments
INNER JOIN Types ON Instruments.Type = Types.ID
INNER JOIN Manufacturer ON Instruments.Manufacturer = Manufacturer.ID
INNER JOIN Facility ON Instruments.Facility = Facility.ID
INNER JOIN Lease ON Instruments.Lease = Lease.ID
WHERE (Types.Description LIKE '%Cat%')
) RawResults
) Results
WHERE (Types.Description LIKE '%Cat%') AND RowNumber BETWEEN 1 AND 10
I think this is your problem
WHERE (types.description LIKE '%Cat%')
You can't do this because you are actually selecting from your derived table named Results and you aliased the column as TypeDesc.
So it should be
WHERE (results.typeDesc LIKE '%Cat%')
select
picks.`fbid`,
picks.`time`,
categories.`name` as cname,
options.`name` as oname,
users.`name`
from
picks
left join categories
on (categories.`id` = picks.`cid`)
left join options
on (options.`id` = picks.oid)
left join users
on (users.fbid = picks.`fbid`)
order by
time desc
that query returns a result that like:
my question is.... I would like to modify the query to select only DISTINCT fbid's. (perhaps the first row only sorted by time)
can someone help with this?
select
p2.fbid,
p2.time,
c.`name` as cname,
o.`name` as oname,
u.`name`
from
( select p1.fbid,
min( p1.time ) FirstTimePerID
from picks p1
group by p1.fbid ) as FirstPerID
JOIN Picks p2
on FirstPerID.fbid = p2.fbid
AND FirstPerID.FirstTimePerID = p2.time
LEFT JOIN Categories c
on p2.cid = c.id
LEFT JOIN Options o
on p2.oid = o.id
LEFT JOIN Users u
on p2.fbid = u.fbid
order by
time desc
I don't know why you originally had LEFT JOINs, as it appears that all picks must be associated with a valid category, option and user... I would then remove the left, and change them to INNER joins instead.
The first inner query grabs for each fbid, the FIRST entry time which will result in a single entity for the FBID. From that, it re-joins to the picks table for the same ID and timeslot... then continues for the rest of the category, options, users join criteria of that single entry.
2 options, you could write a group by clause.
Or you could write a nested query joined back to itself to get pertinent info.
Nested aliased table:
SELECT
n.fBids
FROM
MyTable t
INNER JOIN
(SELECT DISTINCT fBids
FROM MyTable) n
ON n.ID = t.ID
Or group by option
SELECT fBId from MyTable
GROUP BY fBID
select picks.`fbid`, picks.`time`, categories.`name` as cname,
options.`name` as oname, users.`name` from picks left join categories
on (categories.`id` = picks.`cid`) left join options on (options.`id` = picks.oid)
left join users on (users.fbid = picks.`fbid`)
order by time desc GROUP BY picks.`fbid`
select
picks.fbid,
MIN(picks.time) as first_time,
MAX(picks.time) as last_time
from
picks
group by
picks.fbid
order by
MIN(picks.time) desc
However, if you want only distinct fbid's you cannot display cname and other columns at the same time.