SQL Server...
I need to Join tbl_B or tbl_C with tbl_A. Case tblA.id = 1 Join B or Case tblA.id = 2 Join C
let's say this example:
Table: tblFood
Id_Food | Fk_Id_Foodtype
1 | 1
1 | 2
Table: tabVegetable
Id | Mame |Color
1 | eggplant |black
Table: tabFrute
Id | Name |Color
1 | apple |red
On the table tblFood above...
if Fk_Id_Foodtype = 1 join Id_Food on tabVegetable
if Fk_Id_Foodtype = 2 join Id_Food on tabFrute
So I can return execute a select like this: SELECT tblFood.Id_Food, (tabVegetable or tabFrute).name, (tabVegetable or tabFrute).color
Note: I only have tblFruts and tblVegetable, so I always check these two option.
Thank you!
Join to tblFood the other tables with LEFT joins and in the ON clauses specify the condition for Fk_Id_Foodtype.
In the SELECT list of columns use COALESCE() to get the values of the columns from each table:
SELECT f.*,
COALESCE(v.Name, fr.Name) Name,
COALESCE(v.Color, fr.Color) Color
FROM tblFood f
LEFT JOIN tabVegetable v ON f.Fk_Id_Foodtype = 1 AND v.Id = f.Id
LEFT JOIN tabFrute fr ON f.Fk_Id_Foodtype = 2 AND fr.Id = f.Id
Related
I'm currently struggling with carrying out some joins and hoping someone can shed some light on this.
I have three tables: A,B,C
Table C lists names of individuals
Table A lists the food they like to eat
Table B is the link to show what food in A a person likes from C (Our
system was built without foreign keys! I know, it's a pain!)
What I'm trying to write is a query that will return a list of values from Table C which shows the individuals that don't like a specific food...say PFC
I have the following:
select * from table_c c
inner join table_b b
on c.name = b.bValue
inner join table_a a
on b.aValue = a.number
where a.value not in('PFC')
I'm assuming the joins are working but as table A has multiple values, the two extra rows are being returned. Is it possible to not show this client if one of the joins shows a food I don't want to see?
Table A
|---------------------|------------------|
| Number | Value |
|---------------------|------------------|
| 1 | McDs |
|---------------------|------------------|
| 1 | KFC |
|---------------------|------------------|
| 1 | PFC |
|---------------------|------------------|
Table B
|---------------------|------------------|
| bValue | aValue |
|---------------------|------------------|
| John | 1 |
|---------------------|------------------|
Table C
|---------------------|
| Name |
|---------------------|
| John |
|---------------------|
I'm also using SQL Server 2013 if that makes a difference!
With NOT EXISTS:
select * from table_c c
where not exists (
select 1 from table_b b inner join table_a a
on b.aValue = a.number
where b.bValue = c.name and a.value = 'PFC'
)
One option is to aggregate by name:
SELECT
c.Name
FROM table_c c
INNER JOIN table_b b
ON c.Name = b.bValue
INNER JOIN table_a a
ON b.aValue = a.Number
GROUP BY
c.Name
HAVING
COUNT(CASE WHEN a.Value = 'PFC' THEN 1 END) = 0;
We could also try expressing this using an exists query:
SELECT
c.Name
FROM table_c c
WHERE NOT EXISTS (SELECT 1 FROM table_b b
INNER JOIN table_a a
ON b.aValue = a.Number
WHERE c.Name = b.bValue AND
a.Value = 'PFC');
I have a query which will perform joins over 6 tables and fetches various columns based on a condition. I want to add an extra filter condition which will give me only those members who have a count(distinct dateCaptured)>30. I'm able to get the list of members who satisfy this condition using Group by and having. But I don't want to group by other column names because of this one condition. Do I need to use PARTITION BY in this case.
Sample TABLE a
+-----+------------+--------------+
| Id | Identifier | DateCaptured |
+-----+------------+--------------+
| 1 | 05548 | 2017-09-01 |
| 2 | 05548 | 2017-09-01 |
| 3 | 05548 | 2017-09-01 |
| 4 | 05548 | 2017-09-02 |
| 5 | 05548 | 2017-09-03 |
| 6 | 05548 | 2017-09-04 |
| 7 | 37348 | 2017-08-15 |
| 8 | 37348 | 2017-08-15 |
| . | | |
| . | | |
| . | | |
| 54 | 37348 | 2017-10-15 |
+-----+------------+--------------+
Query
SELECT a.value,
b.value, c.value,
d.value
FROM Table a
INNER JOIN Table b on a.Id=b.id
INNER JOIN Table c on a.Id=c.Id and s.Invalid=0
INNER JOIN Table d on a.Id=d.Id
Assume Table a has more than 30 records for Identifier 37348. How can I get only this Identifier for the above query.
These are the patients i'm interested in for the above SELECT.
SELECT a.Identifier,count(DISTINCT DateCaptured)
FROM Table a
INNER JOIN Table b on a.Id=b.id
INNER JOIN Table c on a.Id=c.Id and s.Invalid=0
INNER JOIN Table d on a.Id=d.Id
GROUP BY Identifier
HAVING count(DISTINCT DateCaptured)>30
WITH cte as (
SELECT a.Identifier
FROM Table a
INNER JOIN Table b on a.Id=b.id
INNER JOIN Table c on a.Id=c.Id and s.Invalid=0
INNER JOIN Table d on a.Id=d.Id
GROUP BY Identifier
HAVING count(DISTINCT DateCaptured) > 30
)
SELECT a.value,
b.value, c.value,
d.value
FROM Table a
INNER JOIN Table b on a.Id=b.id
INNER JOIN Table c on a.Id=c.Id and s.Invalid=0
INNER JOIN Table d on a.Id=d.Id
INNER JOIN cte on cte.Identifier = a.Identifier
SELECT a.value,
b.value, c.value,
d.value
FROM Table a
INNER JOIN Table b on a.Id=b.id
INNER JOIN Table c on a.Id=c.Id and s.Invalid=0
INNER JOIN Table d on a.Id=d.Id
WHERE a.Identifier IN (SELECT a1.Identifier
FROM Table a1
GROUP BY a1.Identifier HAVING count(DISTINCT a1.DateCaptured)>30)
If the multiple rows really are in tableA, then you can do:
SELECT a.value, b.value, c.value, d.value
FROM (SELECT a.*, COUNT(*) OVER (PARTITION BY id) as cnt
FROM a
) a INNER JOIN
b
ON a.Id = b.id INNER JOIN
c
ON a.Id = c.Id AND s.Invalid = 0 INNER JOIN
d
ON a.Id = d.Id
WHERE a.cnt > 30;
Note: If you still need count(distinct) you can do:
SELECT a.value, b.value, c.value, d.value
FROM (SELECT a.*, SUM(CASE WHEN seqnum = 1 THEN 1 ELSE 0 END) OVER (PARTITION BY id) as cnt
FROM (SELECT a.*, ROW_NUMBER() OVER (PARTITION BY id ORDER BY DateCaptured) as seqnum
FROM a
) a
) a INNER JOIN
b
ON a.Id = b.id INNER JOIN
c
ON a.Id = c.Id AND s.Invalid = 0 INNER JOIN
d
ON a.Id = d.Id
WHERE a.cnt > 30;
I searched before asking my question:
I have two tables.
Table info:
no | name
1 | david
2 | kang
Table info_kill:
no | staffno | skillno
------------------------
1 | 1 | 1
2 | 2 | 1
3 | 2 | 2
4 | 2 | 3
staffno in info_skill table and no in info table is foreign key.
I want to get:
name contains 'ka'
have skillno 1, 2, 3.
so, this is my sql,
SELECT a.NAME
FROM (SELECT no,
NAME
FROM info
WHERE NAME LIKE '%ka%') AS a
INNER JOIN info_skill AS b
ON a.no = b.staffno
INNER JOIN info_skill AS c
ON a.no = c.staffno
INNER JOIN info_skill AS d
ON a.no = d.staffno
WHERE b.skillno = '1'
AND c.skillno = '2'
AND d.skillno = '3'
what I wonder is this part.
INNER JOIN info_skill AS b
ON a.no = b.staffno
INNER JOIN info_skill AS c
ON a.no = c.staffno
INNER JOIN info_skill AS d
ON a.no = d.staffno
WHERE b.skillno = '1'
AND c.skillno = '2'
AND d.skillno = '3'
Is there any other way?
Try this:
SELECT I.name
FROM info I
JOIN info_skill S
ON I.no = S.staffno
WHERE I.name LIKE'%ka%" AND
S.skillno=1 OR
S.skillno=2 OR
S.skillno=3
This means:
You join the two tables following the foreign key
Then you search for any name containing ka word using LIKE %ka%
Now, you need to check if skillno is equal to 1, 2 or 3
If this is not what you need exactly, then please make your question more clear by explaining what you are looking for exactly.
select a.name
from info a
inner join info_skill as b on a.no = b.staffno
where b.skillno in (1,2,3)
and name like '%ka%'
group by a.name
having count(distinct b.skillno) = 3
SQLFiddle demo
Firstly, I apologize for my English. I want get auctions with count of bids and buys. It should look like this:
id | name | bids | buys
-----------------------
1 | Foo | 4 | 1
2 | Bar | 0 | 0
I have tables like following:
auction:
id | name
---------
1 | Foo
2 | Bar
auction_bid:
id | auction_id
---------------
1 | 1
2 | 1
3 | 1
4 | 1
auction_buy:
id | auction_id
---------------
1 | 1
I can get numbers in two queries:
SELECT *, COUNT(abid.id) AS `bids` FROM `auction` `t` LEFT JOIN auction_bid abid ON (t.id = abid.auction) GROUP BY t.id
SELECT *, COUNT(abuy.id) AS `buys` FROM `auction` `t` LEFT JOIN auction_buy abuy ON (t.id = abuy.auction) GROUP BY t.id
But when i combined it into one:
SELECT *, COUNT(abid.id) AS `bids`, COUNT(abuy.id) AS `buys` FROM `auction` `t` LEFT JOIN auction_bid abid ON (t.id = abid.auction) LEFT JOIN auction_buy abuy ON (t.id = abuy.auction) GROUP BY t.id
It was returning wrong amount (bids as much as buys).
How to fix this and get counts in one query?
You'll need to count DISTINCT abuy and abid IDs to eliminate the duplicates;
SELECT t.id, t.name,
COUNT(DISTINCT abid.id) `bids`,
COUNT(DISTINCT abuy.id) `buys`
FROM `auction` `t`
LEFT JOIN auction_bid abid ON t.id = abid.auction_id
LEFT JOIN auction_buy abuy ON t.id = abuy.auction_id
GROUP BY t.id, t.name;
An SQLfiddle to test with.
Try this:
SELECT t.*,COUNT(abid.id) as bids,buys
FROM auction t LEFT JOIN
auction_bid abid ON t.id = abid.auction_id LEFT JOIN
(SELECT t.id, Count(abuy.id) as buys
FROM auction t LEFT JOIN
auction_buy abuy ON t.id = abuy.auction_id
GROUP BY t.id) Temp ON t.id=Temp.id
GROUP BY t.id
Result:
ID NAME BIDS BUYS
1 Foo 2 0
2 Bar 1 1
Result in SQL Fiddle.
I am having problem with sql join (oracle/ms sql)
I have two tables
A
ID | B_ID
---|------
1 | 1
1 | 4
2 | 3
2 | 2
----------
B
B_ID | B_VA| B_VB
-------|--------|-------
1 | 1 | a
2 | 2 | b
3 | 5 | c
4 | 2 | d
-----------------------
From these two tables I need A.ID, B.B_ID, B.B_VA (MAX), B.B_VB (with max B.B_VA)
So result table would be like
ID | B_ID | B_VA| B_VB
-------|--------|--------|-------
1 | 4 | 2 | d
2 | 3 | 5 | c
I tried some joins without success. Can anyone help me with query to get the result I want.
Thank you
Your logic as described doesn't quite correspond to the data. For instance, b_va is numeric, but the column in the output is a string.
Perhaps you want this. The data in a to be aggregated to get the maximum b_id value. Then each column to be joined to get the corresponding b_vb column. That, at least, conforms to your desired output:
select a.id, a.b_id, b1.b_vb as b_va, b2.b_vb
from (select id, max(b_id) as b_id
from a
group by id
) a join
b b1
on a.id = b1.b_id join
b b2
on a.b_id = b2.b_id;
EDIT:
For the corrected data, I think this is what you want:
select a.id, a.b_id, max(b1.b_va) as b_va, b2.b_vb
from (select id, max(b_id) as b_id
from a
group by id
) a join
b b1
on a.id = b1.b_id join
b b2
on a.b_id = b2.b_id
group by a.id, a.b_id, b2.b_vb;
Try this
SELECT X.ID, Y.B_ID, X.B_VA, Y.B_VB
FROM (SELECT A.ID, MAX(B_VA) AS B_VA
FROM A INNER JOIN B ON A.B_ID = B.B_ID
GROUP BY A.ID) AS X INNER JOIN
A AS Z ON X.ID = Z.ID INNER JOIN
B AS Y ON Z.B_ID=Y.B_ID AND X.B_VA=Y.B_VA