Im am trying to get a list of distinct values from one column whilst getting the key column data by inner join on another table as below..table a and table b hold key column of client.
Table b holds column product which has a range of values against a range of client numbers
Table a holds only client numbet
Table b holds client number and product
Client product
1. A
1. B
2. B
3. C
I want to find the list of distinct product values where the client is in table a and table b
Any suggestions welcome
find the list of distinct product values where the client is in table
a and table b
As you will notice below "distinct" isn't applied in joins
SELECT DISTINCT
b.Product
FROM TABLEA a
INNER JOIN TABLEB b ON a.Client = b.Client
;
The inner join ensures that client exists in both A and B and then the "select distinct" removes any repetition in the list of products.
SELECT
b.Product
, COUNT(*) AS countof
FROM TABLEA a
INNER JOIN TABLEB b ON a.Client = b.Client
GROUP BY
b.Product
;
An alternative, which also makes a distinct list of products where clients are in A and B is to use group by, with the added bonus that this way you can do some extra stuff like counting how often a product is referenced.
try it at SQLFiddle.com
Related
I have a sql that is selecting many things from the database however I would like that data to only comeback which is matched to a personal table I have.
I would like to join a column [vin_code] from my table [population] however there are nulls in here and were there are nulls I would like to join another column from my table to another table in the database.
I will give an example sql below:
Select distinct v.kegal_rntity_id
From vin v
Inner join ops$dami.population pop
On v.vin_code = pop.vin_code
Then were pop.vin_code is null I would like to join pop.vis_code on a table in the database called zegal_rentity z column z.vis_code
So something like
join zegal_rentity z
On pop.vis_code = z.vis_code
But I only want to do this were pop.vin_code is null
As sample data is not available, I am unable to test the solution but try the following query with condition based outer join.
Select distinct v.kegal_rntity_id
From ops$dami.population pop
Left join vin v
On v.vin_code = pop.vin_code
Left join zegal_rentity z
On (case when pop.vin_code is null and
pop.vis_code = z.vis_code then 1 end = 1);
Cheers!!
I have 2 tables.
This is tableA
(invoice,D/O, cost..) and
Table B
(D/O, GRN, Qty)
Now how to use query to show table A include GRN,Qty
See
You need a LEFT OUTER JOIN to retrieve all the records from table A with matched records from table B.
Guessing at the join criteria because your question doesn't say what they are:
select a.*
, b.grn
, b.grn_line
, b.qty_grn
from a
left outer join b
on a.do = b.do
and a.do_line = b.do_line
and a.invoice_line = b.grn_line
I have set of tables in my data base like table A which has set of set of categories , table B set of repositeries. A and B are related by categoryid. And then table C which has set of properties for a repoId. Table C and A are associated with repoId.
Table C can have multiple values for a repoId.
The data in C table is like a property say a number string like 12345XXXX (max data of 10 characters) and I have to find the top 6 matching characters of a particular value in table C and the count of repoIds associated with those top 6 value for a particular data in table A (categoryid).
Table A(set of categories ) ---------> Table B (set of repositories, associated with A with categoryid)---------> Table V (set of FMProperties against a repoId)
Now currently, this has been achieved by using joins and substring queries on these tables and it is very slow.
I have to achieve this functionality using Elastic search. I dont have clear view how to start?
Do I create separate documents / indexes for table A , B and C or fetch the info using sql query and create a single document.
And how we can apply this analytics part explained above.
I am very new and amateur in this technology but I am following the tutorials provided at elasticsearch site.
PFB the query in mysql for this logic:-
select 'fms' as fmstype, C.fmscode as fmsCode,
count(C.repoId) as countOffms from tableC C, tableB B
where B.repoId = C.repoId and B.categoryid = 175
group by C.fmscode
order by countOffms desc
limit 1)
UNION ALL
(select 'fms6' as fmstype, t1.fmscode, t2.countOffms from tableC t1
inner join
(
select substring(C.fmscode,1,6) as first6,
count(C.repoId) as countOffms from tableC C, tableB B
where B.repoId = C.repoId and B.categoryid = 175 and length(C.fmscode) = 6
group by substring(C.fmscode,1,6) order by countOffms desc
limit 1 ) t2
ON
substring(t1.fmscode,1,6) = t2.first6 and length(t1.fmscode) = 6
group by t1.fmscode
order by count(t1.fmscode) desc
limit 1)
1)select count(*) from LCL_RKM_AuditForm; **O/P : 868**
2)select count(*) from RKM_KnowledgeArticleManager; **O/P : 8511**
3)select count(*) from
LCL_RKM_AuditForm A
**right** outer join
RKM_KnowledgeArticleManager B
on A.ARTICLE_ID=B.DocID; **O/P : 9216**
4)select count(*) from
LCL_RKM_AuditForm A
**left** outer join
RKM_KnowledgeArticleManager B
on A.ARTICLE_ID=B.DocID; **O/P : 1973**
5)select count(*) from
LCL_RKM_AuditForm A,RKM_KnowledgeArticleManager B
**where** A.ARTICLE_ID=B.DocID; **O/P : 1973**
My understanding is that.,.
Left outer join will Displays all the values in A table and common values in B table.
Right outer join will Displays all the values in B table and common values in A table.
What does that Common Values refers to ? If its the left outer join which means it should give only 868 results right ? And if its right outer join which means it should give only 8511 results right ?
5th statement i have used WHERE clause which means it should give me only 868 entries right ?
Please help me on this.
Your expected results appear to be based on the false assumption that there is a one-to-one mapping between rows in the two tables.
For a standard inner join (as in your last query), every matching combination of rows from the two tables is returned. Since you are getting more results than there are rows in the first table, it must be true that a given row in the first table may have multiple matching rows in the second table.
For instance, if there is one row in table A with ArticleID = 1, and two rows in Table B with DocID = 1, then a join of the two tables on these fields will produce 2 rows.
When you change to an outer join, you will get at least the same number of rows as the inner join, and potentially more. An outer join will return the same rows as the corresponding inner join; plus, for any row in the "inner" table that does not have any match in the "outer" table, it will return that one row, with NULL values for columns from the second table.
Your LEFT OUTER JOIN returns the same number of rows as the inner join; this implies that every row in table A has at least one matching row in table B.
Your RIGHT OUTER JOIN returns many more rows. This implies that there are many rows in table B that have no matching row in table A.
I had two tables
table1 contains a list of customer and their info and there is a customer id for each one
table2 contains a list of request from all with and customer id for each request as foreign key
and i want to check the customer who has request and who is not
plz how should that be done logical is it possible to eqaul between two queries ?
thanks
You have two tables, the first with one row per customer, the other with zero to many rows per customer. So you need two techniques: one to reduce the second table to one row per customer and the other to join that result set to the first table. These techniques are an aggregating sub-query and an outer join respectively.
select c.customer_id
, nvl(r.req_count, 0) as no_of_reqs
from customer c
left outer join ( select customer_id
, count(*) as req_count
from customer_req
group by customer_id ) r
on c.customer_id = r.customer_id