I am trying to figure out a way to identify all ID's that only contain all of the same value in another column.
In the example above Looking for all SubID's that are inactive it would only return rows for C2 (ID's 2, 5, & 6).
Sample Data :
You use not exists :
select t.*
from table t
where not exists (select 1 from table t1 where t1.subid = t.subid and t1.status = 'Active');
EDIT : If you want to get the subids which have same status then you can do :
select t.*
from table t
where not exists (select 1 from table t1 where t1.subid = t.subid and t1.status <> t.status);
use group by and sub-query
select t.* from
(select subid,status from t t1
group by subid,status
having count(*)>1
) as t1
inner join t on t.subid=t1.subid and t.status=t1.status
Related
I am currently trying to join a table to itself to check if for one email there exist two or more Ids.
I am trying to join my table with itself on its email. I then wanted to query my table with a case condition saying if the count of the email in the nested query > 1 then select the latest modified record in the outer table.
SELECT *
FROM table1 <-- outer table
WHERE email IN
(SELECT email, COUNT(*)
FROM table1 as src
INNER JOIN table1 ON src.Email = table1.Email AND src.Id = table1.id
GROUP BY src.Email)
How can I write a query to say if the count for the given email is greater than 1 then select the latest record from the outer table?
Why would you go through all that trouble? How about just selecting the last modified record:
select t1.*
from table1 t1
where t1.modified_dt = (select max(tt1.modified_dt)
from table1 tt1
where tt1.email = t1.email
);
Another way to do it using window functions:
DECLARE #Tab TABLE (ID INT, Email VARCHAR(100), LastModified DATE)
INSERT #Tab
VALUES (1,'testemail#none.com','2019-12-01'),
(2,'testemail#none.com','2019-11-19'),
(3,'otheremail#none.com','2019-12-15')
SELECT *
FROM(
SELECT ROW_NUMBER() OVER(PARTITION BY t.Email ORDER BY t.LastModified DESC) rn, t.*
FROM #Tab t
) t2
WHERE t2.rn = 1
If by latest you mean the latest id number (the maximum number) then this should help you
With cte AS
(
SELECT email,
COUNT(id) OVER (PARTITION BY email) AS CountOfIDs,
ROW_NUMBER() OVER (PARITION BY email ORDER BY ID DESC) AS IdIndex
FROM table1
)
SELECT *
FROM cte
WHERE CountOfIDs > 1 AND IdIndex = 1
I have a table called purchase contracts
I want to select the contracts having the same supplier but different purchasers.
This is how the data looks like (C1= Contract, C2= supplier, C3= purhaser)
Dataset
I want to create a select which results in showing rows 4, 5 & 6
I've tried solution from this tread, but didn't work
Select rows with same id but different value in another column
You can use exists
select t.*
from table t
where exists (select 1 from table t1 where t1.c2 = t.c2 and t1.c3 <> t.c3);
You can use exists:
select t.*
from t
where exists (select 1
from t t2
where t2.c2 = t.c2 and t2.c3 <> t.c3
);
I'm trying to figure out how to retrieve all rows with a ID which have a specific value in the other column.
The database looks like this:
I want to retrieve those rows which have a VAL of 2 and the corresponding ID rows. So in this case this would give me all the ID 1 rows and the ID 3 row:
you'll need a subquery (or join or cte or derived table) Subquery is easist to visualise
Select * from Test where ID IN
(SELECT ID from Test where VAL = 2)
One method is exists:
select t.*
from test t
where exists (select 1 from test t2 where t2.id = t.id and t2.val = 2);
Constructions like where id in (select id from ...) and where exists (select 1 from ...) may take very long time, because for every row in test you are executing subquery. To solve your problem you can join test with itself and make distinct like this:
SELECT DISTINCT t1.*
FROM test t1
INNER JOIN test t2 ON t1.id = t2.id
WHERE t2.val = 2
I have two tables with the same structure:
id name
1 Merry
2 Mike
and
id name
1 Mike
2 Alis
I need to union second table to first with keeping unique names, so that result is:
id name
1 Merry
2 Mike
3 Alis
Is it possible to do this with MySQL query, without using php script?
This is not a join (set multiplication), this is a union (set addition).
SELECT #r := #r + 1 AS id, name
FROM (
SELECT #r := 0
) vars,
(
SELECT name
FROM table1
UNION
SELECT name
FROM table2
) q
This will select all names from table1 and combine those with all the names from table2 which are not in table1.
(
select *
from table1
)
union
(
select *
from table2 t2
left join table1 t1 on t2.name = t1.name
where t1.id is null
)
Use:
SELECT a.id,
a.name
FROM TABLE_A a
UNION
SELECT b.id,
b.name
FROM TABLE_B b
UNION will remove duplicates.
As commented, it all depends on what your 'id' means, cause in the example, it means nothing.
SELECT DISTINCT(name) FROM t1 JOIN t2 ON something
if you only want the names
SELECT SUM(something), name FROM t1 JOIN t2 ON something GROUP BY name
if you want to do some group by
SELECT DISTINCT(name) FROM t1 JOIN t2 ON t1.id = t2.id
if the id's are the same
SELECT DISTINCT COALESCE(t1.name,t2.name) FROM
mytable t1 LEFT JOIN mytable t2 ON (t1.name=t2.name);
will get you a list of unique names from the 2 tables. If you want them to get new ids (like Alis does in your desired results), that's something else and requires the answers to a couple of questions:
do any of the names need to maintain their previous id. And if they do, which table's id should be preferred?
why do you have 2 tables with the same structure? ie what are you trying to accomplish when you generate the unique name list?
I need to create a background job that processes a table looking for rows matching on a particular id with different statuses. It will store the row data in a string to compare the data against a row with a matching id.
I know the syntax to get the row data, but I have never tried comparing 2 rows from the same table before. How is it done? Would I need to use variables to store the data from each? Or some other way?
(Using SQL Server 2008)
You can join a table to itself as many times as you require, it is called a self join.
An alias is assigned to each instance of the table (as in the example below) to differentiate one from another.
SELECT a.SelfJoinTableID
FROM dbo.SelfJoinTable a
INNER JOIN dbo.SelfJoinTable b
ON a.SelfJoinTableID = b.SelfJoinTableID
INNER JOIN dbo.SelfJoinTable c
ON a.SelfJoinTableID = c.SelfJoinTableID
WHERE a.Status = 'Status to filter a'
AND b.Status = 'Status to filter b'
AND c.Status = 'Status to filter c'
OK, after 2 years it's finally time to correct the syntax:
SELECT t1.value, t2.value
FROM MyTable t1
JOIN MyTable t2
ON t1.id = t2.id
WHERE t1.id = #id
AND t1.status = #status1
AND t2.status = #status2
Some people find the following alternative syntax easier to see what is going on:
select t1.value,t2.value
from MyTable t1
inner join MyTable t2 on
t1.id = t2.id
where t1.id = #id
SELECT COUNT(*) FROM (SELECT * FROM tbl WHERE id=1 UNION SELECT * FROM tbl WHERE id=2) a
If you got two rows, they different, if one - the same.
SELECT * FROM A AS b INNER JOIN A AS c ON b.a = c.a
WHERE b.a = 'some column value'
I had a situation where I needed to compare each row of a table with the next row to it, (next here is relative to my problem specification) in the example next row is specified using the order by clause inside the row_number() function.
so I wrote this:
DECLARE #T TABLE (col1 nvarchar(50));
insert into #T VALUES ('A'),('B'),('C'),('D'),('E')
select I1.col1 Instance_One_Col, I2.col1 Instance_Two_Col from (
select col1,row_number() over (order by col1) as row_num
FROM #T
) AS I1
left join (
select col1,row_number() over (order by col1) as row_num
FROM #T
) AS I2 on I1.row_num = I2.row_num - 1
after that I can compare each row to the next one as I need