Am trying to execute the below update statement in H2
UPDATE table1
SET STATUS_CD = 1
WHERE (col1, col2)
IN (select col1, col2 FROM table2)
but it produces Subquery is not a single column query
Use Exists
UPDATE table1 t1
SET STATUS_CD = 1
WHERE exists (Select 1 FROM table2 t2 where t1.col1 = t2.col1 and t1.col2 = t2.col2)
Related
I am trying to use the below query, its everytime saying cannot insert null for the second column.
UPDATE TABLE1
SET (COL1,COL2,COL3) = (SELECT COL1,COL2,COL3
FROM TABLE2
WHERE t1.id = t2.id);
Try this:
UPDATE TABLE1 SET (COL1,COL2,COL3) =
(SELECT COL1,NVL(COL2,0),COL3 FROM TABLE1 T1, TABLE2 T2 where t1.id = t2.id)
WHERE <YOUR WHERE CONDITION>
I would use a MERGE:
MERGE INTO TABLE1 t1
USING (SELECT id, COL1,COL2,COL3
FROM TABLE2) t2
ON (t1.id = t2.id)
WHEN MATCHED THEN UPDATE SET t1.COL1 = t2.COL1
, t1.COL2 = t2.COL2
, t1.COL3 = t2.COL3;
There are rows in table1 where not corresponding row exists in table2 thus the sub-query returns nothing which means the UPDATE statement will take that as null for all three columns.
You have to add a WHERE clause that only updates rows in table1 that do have a matching row in table2
UPDATE TABLE1
SET (COL1,COL2,COL3) = (SELECT COL1,COL2,COL3
FROM TABLE2 t2
WHERE table1.id = t2.id)
where exist (select *
from table2 t2
where table1.id = t2.id);
Let's say I have two tables t1 and t2.
t1 has two integer cols col1 (primary) and col2
t2 has two cols a foreign key of t1.col1 and t2.col2
I want to do the following
Retrieve only the records where t1.col2 is unique OR if t1.col2 is duplicate only those if t2.col2 is not null.
Insert the above records into another summary table, let's say t3
This is what I tried:
insert into t3 (col1,col2)
select col1, col2
from t1
where t.col1 in (select A.col1 from t1 as A
group by 1
having count(*) > 1
union
select col1, col2
from t1, t2
where t.col1 in (select A.col1 from t1 as A
group by 1
having count(*) > 1
and t2.col2 is not null;
While the 'union qry' works on its own, the insert is not happening.
Any ideas or any other efficient way to achieve this please
You can select the records you want using:
select t1.*
from (select t1.*, count(*) over (partition by col2) as cnt
from t1
) t1
where cnt = 1 or
exists (select 1 from t2.col1 = t1.col1 and t2.col2 is null);
The rest is just an insert.
Update table1 t1
set t1. col1='op'
where t1.col2 in (select t2.col2 from table2 t2 where t1.col3 = t2.col3) ;
The above query is working in Oracle but not in SQL server.
Throwing error: incorrect syntax near t1.
You can't set an alias in the UPDATE clause in SQL Server. The correct syntax would be to drop the alias or alias the object in the FROM:
--Without Alias
UPDATE table1
SET col1 = 'op'
WHERE EXISTS (SELECT 1
FROM Table2 AS T2
WHERE T2.col3 = table1.col3
AND T2.col2 = table1.col2);
--FROM and JOIN
UPDATE T1
SET col1 = 'op'
FROM Table1 AS T1
JOIN Table2 AS T2 ON T1.Col2 = T2.Col2
AND T1.Col3 = T2.Col3;
--With Aliases
UPDATE T1
SET col1 = 'op'
FROM Table1 AS T1
WHERE EXISTS (SELECT 1
FROM Table2 AS T2
WHERE T2.col3 = table1.col3
AND T2.col2 = table1.col2);
We have a SQL query which is not written as per the sql guideline. We have to change the query but if we change the logic and remove the inner query then it take to much time to execute. Below is the query:
select col1,
col2,
case
when col1 <> '' then(select top 1
col1
from table1 as BP
where bp.col1 = FD.col1 order by BP.col1)
when col2 <> '' then(select top 1
BP.col2
from table1 as BP
where BP.col2 = FD.col2 order by BP.col2)
else ''
end
from table2 FD
The above query is being used to insert the data into a temp table. The table1 has almost 100 million of data. Is there any way to remove the inline query along with the good performance. We have already created the indexes on table1. Any thought?
Try this
;WITH CTE
AS
(
SELECT
RN = ROW_NUMBER() OVER(ORDER BY COALESCE(T2.col1,T2.col2)),
T2.col1,
T2.col2,
T1Val = COALESCE(T2.col1,T2.col2,'')
FROM table2 T2
LEFT JOIN table1 T1
ON
(
(
ISNULL(T2.col1,'')<>'' AND T1.col1 = T2.col1
)
OR
(
ISNULL(T2.col2,'')<>'' AND T1.col2 = T2.col2
)
)
)
SELECT
*
FROM CTE
WHERE RN = 1
Here is my modest help:
You can already prepare and materialize your subquery1 and subquery2 (Group BY col1 or col2) <-- It will reduce the size of your table 1)
Split your main query (from table2 into 3 different queries)
1 with SELECT .. FROM table2 WHERE col1 <> ''
1 with SELECT .. FROM table2 WHERE col1 = '' AND col2 <> ''
1 with SELECT .. FROM table2 WHERE col1 = '' AND col2 = ''
Use an INNER JOIN with your table created in the first point.
(If you use SSIS you can // and use your inner join table into a Lookup)
If your col1 or col2 use a NVARCHAR(MAX) or a big size, you should have a look to a HashFunction (MD5 for example) and compare Hash instead.
Be sure to have all your indexes
At least if it is not performant, you can try with:
OUTER APPLY (SELECT TOP 1 .. )
Another idea should be:
SELECT col1, col2, col1 AS yourNewCol
FROM table2 T2
WHERE EXISTS( SELECT 1 FROM table1 T1 WHERE T1.col1 = T2.col1)
UNION ALL
SELECT col1, col2, col2 AS yourNewCol
FROM table2 T2
WHERE
NOT EXISTS( SELECT 1 FROM table1 T1 WHERE T1.col1 = T2.col1)
AND EXISTS( SELECT 1 FROM table1 T1 WHERE T1.col2 = T2.col2)
UNION ALL
...
I don't have a clean solution for you, but some ideas.
Let me know if it helps you.
Regards,
Arnaud
I try to update one table based on values found in another table. The following works:
UPDATE table1 SET col1 = ( SELECT col1 from table2 WHERE table2.col1 = table1.col1 );
I want to do the same using several columns. I thought the following should bring the desired result"
UPDATE table1 SET (col1, col2) = ( SELECT col1, col2 from table2 WHERE table2.col1 = table1.col1 );
but I get a
syntax error at or near "SELECT"
LINE 1: UPDATE table1 SET (col1, col2) = ( SELECT col1, col2 f...
Any help appreciated.
This should work:
update table1 t1
set col1 = t2.col1,
col2 = t2.col2
from table2 t2
where t1.col1 = t2.col1;
SQL Fiddle Demo
With that said, no need to update col1 = t2.col1 since that is your join criteria.