I have two tables T1 and T2, both of them contain a column ID and value.
I need to join T1 and T2 into T3 by means of ID.
T3 should contain columns ID, T1Value, and T2Value.
The main requirement is, ID of T1 and T2 is possible not mapped
T1:
ID VALUE
-----------
1 hi
2 hello
T2:
ID VALUE
----------
2 kitty
3 dog
Then, T3 should be
ID T1VALUE T2VALUE
----------------------
1 hi
2 hello kitty
3 dog
Is it possible to achieve this without using pivot table, or temp table (ideally should be a single executable query)?
Thanks.
You can use FULL OUTER JOIN
SELECT ID = COALESCE(T1.ID, T2.ID),
T1VALUE = T1.VALUE,
T2VALUE = T2.VALUE
FROM T1
FULL OUTER JOIN T2
ON T1.ID = T2.ID
There are lots of example on FULL OUTER JOIN . just search for it
Another way is to use UNION ALL
SELECT T1.ID, T1VALUE = T1.VALUE, T2VALUE = NULL
FROM T1
UNION ALL
SELECT T2.ID, T1VALUE = NULL, T2VALUE = T2.VALUE
FROM T2
Related
I have two tables t1 and t2.
t1 having 10k records and t2 having 2k records. The 2k records of t2 is present in t1.
I wanted the 8k different records from t1 which is not present in t2.
I'm doing this as below:
select id, second_telphon from t1
except
select id, second_telphon from t2
However, I'm still getting all the 10k records. Is "except" keyword not working?
how can I achieve this?
you can perform a Join to get the unique data from the tables .
like the tables t1 & t2 both you cna perform left or right join .
example:
SELECT T1.*
FROM T1
WHERE NOT EXISTS(SELECT NULL
FROM T2
WHERE T1.ID = T2.ID
AND T1.Date = T2.Date
AND T1.Hour = T2.Hour)
OR .
SELECT T1.*
FROM T1
LEFT JOIN T2
ON T1.ID = T2.ID
AND T1.Date = T2.Date
AND T1.Hour = T2.Hour
WHERE T2.ID IS NULL
Try this:
SELECT *
FROM T1
WHERE NOT EXISTS(SELECT id,second_telphon FROM t2)
If ID is a unique value, Try this also:
SELECT *
FROM T1
WHERE ID NOT IN(SELECT ID FROM t2)
You could try a union, followed by an aggregation to restrict to those records in the first table which were not duplicated by the second table:
SELECT id, second_telphon
FROM
(
SELECT id, second_telphon FROM t1
UNION ALL
SELECT id, second_telphon FROM t2
) t
GROUP BY id, second_telphon
HAVING COUNT(*) = 1;
If a record, being defined as an id, second_telphon pair, has a record count of only one after the union, it implies that this record was unique to the first table.
Just do left join
select t1.id,t1.second_telphon from t1
left join t2 on
t1.id = t2.id
and t1.second_telphon =t2.second_telphon
where t2.id is null
I have 3 tables :
t1 : id, m_id, date
t2 : p_id, p_code
t3 : p_id, p_code, event_id
How do I update the ids in t1?
where id in (select p_id from t2 inner join t3 on t2.p_code = t3.p_code)
UPDATE t1
SET id = (SELECT TOP 1 t2.p_id
FROM t2 INNER JOIN t3
WHERE t2.p_code = t3.p_code)
WHERE <conditon> -- choose rows to update
I have two tables as shown below.
Id Name Id Status
-------- -------------------
1 A 1 Approved
2 B 6 Approved
3 C 4 Pending
4 D 1 Approved
5 E 1 Pending
6 F 3 Pending
5 Rejected
Now this is how I want the output to be:
Id Name Status
-------------------
1 A Pending
2 B
3 C Pending
4 D Pending
5 E
6 F
I have tried using left join but I am getting multiple rows.
select t1.ID,Name,Status from t1 left join t2 on t1.id=t2.id
and if I add where Status=pending i am getting only ids 1 and 3.
Here are the queries i tried:
select distinct t1.id,name,status from t1 left join t2 on t1.id=t2.id (this gives me duplicate records i.e id 1 is occurs twice with approved and pending)
and also
select distinct t1.id,name,status from t1 left join t2 on t1.id=t2.id where t2.status='pending' (gives me only 1,3 and 4)
Could any one help me,
Thanks in advance.
To include all rows from T1 and only those from T2 with status = 'pending' move the condition into the ON clause SQL Fiddle
SELECT t1.ID,
Name,
Status
FROM t1
LEFT JOIN t2
ON t1.id = t2.id
AND t2.status = 'pending'
To only return one row per id in the event of dupes you could do (Fiddle)
WITH CTE AS
(
SELECT DISTINCT id, Status
FROM T2
WHERE Status = 'Approved'
)
SELECT t1.ID,
Name,
Status
FROM t1
LEFT JOIN CTE
ON t1.id = CTE.id
I have two tables with identical definition.
T1:
Name VARCHAR(50)
Qty INT
T2:
Name VARCHAR(50)
Qty INT
This is the data each table has:
T1:
Name Qty
a 1
b 2
c 3
d 4
T2:
Name Qty
a 1
b 3
e 5
f 10
I want to have result which can sum the Qty from both the tables based on Name.
Expected resultset:
Name TotalQty
a 2
b 5
c 3
d 4
e 5
f 10
If am do Left Join or Right Join, it is not going to return me the Name from either of the tables.
What i am thinking is to create a temp table and add these records and just do a SUM aggregate on Qty column but i think there should be a better way to do this.
This is how my query looks like which does not return the expected resultset:
SELECT t1.Name, ISNULL(SUM(t1.Qty + t2.Qty),0) TotalQty
FROM t1
LEFT JOIN t2
ON t1.Name = T2.Name
GROUP BY t1.Name
Can someone please tell me if creating a temp table is OK here or there is a better way to do this?
You can use a full outer join:
SELECT
ISNULL(t1.Name, t2.Name) AS Name,
ISNULL(t1.Qty, 0) + ISNULL(t2.Qty, 0) AS TotalQty
FROM t1
FULL JOIN t2 ON t1.Name = T2.Name
See it working online: sqlfiddle
You can use a UNION ALL to select both tables as one, since they have the same definition. From there, you can nest them as a derived table, and then SUM on that:
SELECT [Name], SUM(Qty) AS TotalQty
FROM (
SELECT [Name], Qty
FROM t1
UNION ALL
SELECT [Name], Qty
FROM t2
) YourDerivedTable
GROUP BY [Name]
This should be simple enough, but somehow my brain stopped working.
I have two related tables:
Table 1:
ID (PK), Value1
Table 2:
BatchID, Table1ID (FK to Table 1 ID), Value2
Example data:
Table 1:
ID Value1
1 A
2 B
Table 2:
BatchID Table1ID Value2
1 1 100
2 1 101
3 1 102
1 2 200
2 2 201
Now, for each record in Table 1, I'd like to do a matching record on Table 2, but only the most recent one (batch ID is sequential). Result for the above example would be:
Table1.ID Table1.Value1 Table2.Value2
1 A 102
2 B 201
The problem is simple, how to limit join result with Table2. There were similar questions on SO, but can't find anything like mine. Here's one on MySQL that looks similar:
LIMITing an SQL JOIN
I'm open to any approach, although speed is still the main priority since it will be a big dataset.
WITH Latest AS (
SELECT Table1ID
,MAX(BatchID) AS BatchID
FROM Table2
GROUP BY Table1ID
)
SELECT *
FROM Table1
INNER JOIN Latest
ON Latest.Table1ID = Table1.ID
INNER JOIN Table2
ON Table2.BatchID = Latest.BatchID
SELECT id, value1, value2
FROM (
SELECT t1.id, t2.value1, t2.value2, ROW_NUMBER() OVER (PARTITION BY t1.id ORDER BY t2.BatchID DESC) AS rn
FROM table1 t1
JOIN table2 t2
ON t2.table1id = t1.id
) q
WHERE rn = 1
Try
select t1.*,t2.Value2
from(
select Table1ID,max(Value2) as Value2
from [Table 2]
group by Table1ID) t2
join [Table 1] t1 on t2.Table1ID = t1.id
Either GROUP BY or WHERE clause that filters on the most recent:
SELECT * FROM Table1 a
INNER JOIN Table2 b ON (a.id = b.Table1ID)
WHERE NOT EXISTS(
SELECT 1 FROM Table2 c WHERE c.Table1ID = a.id AND c.BatchID > b. BatchID
)