I am trying to join two tables. I want to join where all the three identifiers (Contract id, company code and book id) are a match in both tables, if not match using contract id and company code and the last step is to just look at contract id
Can the task be performed wherein you join using all three parameters, if does not, check the two parameters and then just the contract id ?
Code:
SELECT *
INTO #prem_claim_wtauto_test
FROM #contract_detail A
LEFT JOIN #claim_total C
ON ( ( C.contract_id_2 = A.contract_id
AND C.company_cd_2 = A.company_cd
AND C.book_id_2 = A.book_id )
OR ( C.contract_id_2 = A.contract_id
AND C.company_cd_2 = A.company_cd )
OR ( C.contract_id_2 = A.contract_id ) )
Your ON clause boils down to C.contract_id_2 = A.contract_id. This gets you all matches, no matter whether the most precise match including company and book or a lesser one. What you want is a ranking. Two methods come to mind:
Join on C.contract_id_2 = A.contract_id, then rank the rows with ROW_NUMBER and keep the best ranked ones.
Use a lateral join in order to only join the best match with TOP.
Here is the second option. You forgot to tell us which DBMS you are using. SELECT INTO looks like SQL Server. I hope I got the syntax right:
SELECT *
INTO #prem_claim_wtauto_test
FROM #contract_detail A
OUTER APPLY
(
SELECT TOP(1) *
FROM #claim_total C
WHERE C.contract_id_2 = A.contract_id
ORDER BY
CASE
WHEN C.company_cd_2 = A.company_cd AND C.book_id_2 = A.book_id THEN 1
WHEN C.company_cd_2 = A.company_cd THEN 2
ELSE 3
END
);
If you want to join all rows in case of ties (e.g. many rows matching contract, company and book), then make this TOP(1) WITH TIES.
Related
SELECT GARAGE, MAKE
FROM NEIGHBORHOOD_TABLE A
JOIN VEHICLES_TABLE B ON B.MAKE = A.MAKE DISTINCT BY B.MAKE
WHERE A.ZIPCODE = MY_ZIP_CODE
;
Now I want to return all the garages in my zip code with a FORD make. Now the Vehicles-Table can have multiple Models of FORD Makes on the join but I only want to return 1 row for FORD make not all the models FUSION, RANGER, F150....probably a bad example but the Idea is I want to return multiple rows from Table A that Match Table B however Table B may have multiple rows that match table A but I want only 1 row, sort of distinct by B.MAKE.
This is a DB2 SQL database.
Thanks if you can figure out what I am asking.
The simplest solution I can think of is to use ROW_NUMBER(). For example
select *
from (
select
a.garage,
a.make,
row_number() over(partition by a.make order by b.id) as rn
from neighborhood_table a
join vehicles_table b on b.make = a.make
where a.zipcode = 12345
) x
where rn = 1
Note that you need to add an ordering criteria to decide which row to pick when there are multiple ones per make; I added order by b.id but you should change according to your criteria.
Alternatively, you can use a lateral query to get a single row per group.
Try this:
SELECT A.GARAGE, A.MAKE
FROM NEIGHBORHOOD_TABLE A
JOIN
(
SELECT DISTINCT MAKE
FROM VEHICLES_TABLE
) B ON B.MAKE = A.MAKE
WHERE A.ZIPCODE = MY_ZIP_CODE
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
Can someone help explain to me how when I have 12 rows in table A and 10 in B and I do an inner join , I would get more rows than
in both A and B ?
Same with left and right joins...
This is just a simplified example. Let me share one of my issues with you
I have 2 views ; which was originally SQL on 2 base tables Culture and Trials.
And then when attempting to add another table Culture Steps, one of the team members separated the SQL into 2 views
Since this produces an error when updating(modification cannot be done as it affects multiple base tables), I would like to get
back to changing the SQL such that I no longer use the views but achieve the same results.
One of the views has
SELECT some columns
FROM dbo.Culture RIGHT JOIN
dbo.Trial ON dbo.Culture.cultureID = dbo.Trial.CultureID LEFT OUTER JOIN
dbo.TrialCultureSteps_view_part1 ON dbo.Culture.cultureID = dbo.TrialCultureSteps_view_part1.cultureID
The other TrialCultureSteps_view_part1 view
SELECT DISTINCT dbo.Culture.cultureID,
(SELECT TOP (1) WeekNr
FROM dbo.CultureStep
WHERE (CultureID = dbo.Culture.cultureID)
ORDER BY CultureStepID) AS normalstartweek
FROM dbo.Culture INNER JOIN
dbo.CultureStep AS CultureStep_1 ON dbo.Culture.cultureID = CultureStep_1.CultureID
So how can I combine the joins the achieve the same results using SQL only on tables without the need for views?
Welcome to StackOverflow! This link might be a good place to start in your understanding of JOINs. Essentially, the 'problem' you describe boils down to the fact that one or more of your sources (Trial, Culture, or the TrialCultureSteps view) has more than one record per CultureID - in other words, the same CultureID (#1) shows up on multiple rows.
Based solely on that ID, I'd execute the following three queries. Anything that is returned by them is the 'cause' of your duplications - the culture ID shows up more than once, so you'll have to JOIN on more than just CultureID. If, as I half-suspect, your view is the one that has multiple Culture IDs, you'll need to modify it to only return one record, or change the way that you JOIN to it.
SELECT *
FROM Trial
WHERE CultureID IN
(
SELECT CultureID
FROM Trial
GROUP BY CultureID
HAVING COUNT(*) > 1
)
ORDER BY CultureID
SELECT *
FROM Culture
WHERE CultureID IN
(
SELECT CultureID
FROM Culture
GROUP BY CultureID
HAVING COUNT(*) > 1
)
ORDER BY CultureID
SELECT *
FROM TrialCultureSteps_view_part1
WHERE CultureID IN
(
SELECT CultureID
FROM TrialCultureSteps_view_part1
GROUP BY CultureID
HAVING COUNT(*) > 1
)
ORDER BY CultureID
Let me know if any of these return values!
The comments explain the JOIN issues. As for rewriting, any views could be replaced with CTEs.
One other way to rewrite the query, would be : (Though having sample data and expected result would make this easier to confirm that it's correct)
;with TrialCultureSteps_view_part1 AS
(
Select Row_number() OVER (Partition BY CultureID ORDER BY CultureStepID) RowNumber
, WeekNr
, CultureID
)
SELECT some columns
dbo.trial LEFT OUTER JOIN
dbo.Culture ON dbo.Culture.cultureID = dbo.Trial.CultureID LEFT OUTER JOIN
TrialCultureSteps_view_part1 ON dbo.Culture.cultureID = dbo.TrialCultureSteps_view_part1.cultureID and RowNumber=1
Access code, I'm less familiar with the syntax, but I know that Row_Number() isn't available and I don't believe it has CTE syntax either. So, we'd need to put in some more nested derived tables.
SELECT some columns
dbo.trial LEFT OUTER JOIN
dbo.Culture ON dbo.Culture.cultureID = dbo.Trial.CultureID LEFT OUTER JOIN
( Select cs.CultureID, cs.WeekNr FROM
( SELECT CultureID, MIN(CultureStepID) CultureStepID
FROM dbo.CultureStep
GROUP BY CultureID
) Fcs INNER JOIN
CultureStep cs ON fcs.cultureStepID=cs.CultureStepID
) TrialCultureSteps_view_part1 ON dbo.Culture.cultureID = TrialCultureSteps_view_part1.cultureID
Assumptions here, is that CultureStepID is a PK for CultureStep. No assumption that a step must exist for each Culture entry.
i have this code and i want someone to help me to change it to a grouped query which orders froms below.
SELECT *
FROM dbo.users_pics INNER JOIN profile
ON users_pics.email = profile.email
Left Join photo_comment
On users_pics.u_pic_id = photo_comment.pic_id
WHERE users_pics.wardrobe = MMColParam
ORDER BY u_pic_id asc
what i mean is i have grouped of records which i want to select one per record only from beneath. for example if i have 10 records of the name "John" i want to select the last "John" out of the 10 and then the rest also follows
I'm going to presume that your users table contains a single user, and each user has a single profile, and your photo_comment table can contain multiple comments.
Depending on your RDBMS, you can do this a number of ways. Row_Number can often be a quick way of doing this if you're using a database which supports window functions such as SQL Server or Oracle.
A generic solution to this is to join the table back to itself using the MAX aggregate. This is dependent on having a field to determine which record is the max. Generally speaking, that would be an identity/auto number field or a time stamp field.
Here is the basic concept using photo_comment_id as your determining column:
SELECT *
FROM dbo.users_pics INNER JOIN profile
ON users_pics.email = profile.email
LEFT Join (
SELECT pic_id, MAX(photo_comment_id) max_photo_comment_id
FROM max_photo_comment
GROUP BY pic_id
) max_photo_comment On users_pics.u_pic_id = max_photo_comment.pic_id
LEFT Join photo_comment On
max_photo_comment.pic_id = photo_comment.pic_id AND
max_photo_comment.max_photo_comment_id = photo_comment.photo_comment_id
WHERE users_pics.wardrobe = MMColParam
ORDER BY u_pic_id asc
If your database supports ROW_NUMBER, then you can do this as well (still using the photo_comment_id field):
SELECT *
FROM (
SELECT *,
ROW_NUMBER() OVER (PARTITION BY photo_comment.pic_id
ORDER BY photo_comment.photo_comment_id DESC) rn
FROM dbo.users_pics INNER JOIN profile
ON users_pics.email = profile.email
LEFT JOIN photo_comment
ON users_pics.u_pic_id = photo_comment.pic_id
WHERE users_pics.wardrobe = MMColParam
) t
WHERE rn = 1
ORDER BY u_pic_id asc
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.