Is it possible to update multiple tables in Oracle with a single query using join? If so, what is the syntax? My colleague said he had done it in MySQL.
Update- What I am trying to do is something like this
UPDATE table1 t1 JOIN table2 t2 ON t1.id = t2.id SET t1.column1 = 'ABC', t2.column2 = 'BCD' WHERE <condition>
What problem are you trying to solve? You cannot use a single update statement in Oracle to update multiple tables, but it is possible using a "Instead-Of" trigger on a view.
Related
I need to use Select Query results ( having Sub query) as source. This results needs to join with another source table.
Hi All,
I need to use Select Query results ( having Sub query) as source. This results needs to join with another source table.
Ex: Select A,B from (Select t1.a as A, t1.b as B from table1 t1,table t2 where t1.a=t2.b)
In 11g, we've yellow interface where we can write custom queries and invoke that into blue interface for joining with another table.
I'm looking for similar options in 12c
There are two tables in my database. I am trying to update a column in table2 by setting it equal to one of the columns in table1. I've already looked at this answer visual foxpro - need to update table from another table
And tried to do this on my code, however, I kept having a syntax error on UPDATE table2. Why?
Here is what I have.
ALTER TABLE table2;
ADD COLUMN base2 B(8,2);
UPDATE table2
WHERE table2.itemid=table1.itemid from table1;
SET table2.base2=table1.base;
The simplest syntax is:
update table2 from table1 where table2.itemid = table1.itemid ;
set table2.base2 = table1.base
You could also add more fields to update separated by commas, i.e.
... set table2.base2 = table1.base, table2.this = table1.that
Using 'standard' VFP language syntax and RELATED Tables, you could quite easily do the following:
USE Table1 IN 0 EXCLUSIVE
SELECT Table1
INDEX ON ID TAG ID && Create Index on ID field
USE Table2 IN 0
SELECT Table2
SET RELATION TO ID INTO Table1
REPLACE ALL Table2.ID WITH Table1.ID FOR !EMPTY(Table2.ID)
You might want to spend some time looking over the free, on-line tutorial videos at: Learn Visual Foxpro # garfieldhudson.com
The videos named:
* Building a Simple Application - Pt. 5
and
* Q&A: Using Related Tables In A Report
Both discuss using VFP's language to work with Related Tables
Good Luck
Use join
Update table2 b
Join table1 a on b. Itemid=a.itemid
Set b. Base2=a.base
I’m joining 2 tables. Pruning is happening on table 1 but not on table 2 even though there is an outer join.
Example:
select *
from table1 t1, table2 t2
where t1.sk in (select sk from filter_table)
and t2.sk(+) = t1.sk
When I check the plan and noticed t1 table has KEY partition scan, but T2 is scanning all the partition(~4500). so the query is taking more than 4hrs just to pull 50 recs.
Is there any way to force the pruning on table 2 as well?
I am using Oracle 11g.
Without more data it is hard to say for sure what the problem can be. I have rewritten the query for clarity and with a simple test schema I get pruning for both tables with Oracle 12c (I don't have 11g handy). The first with key and the second with Bloom Filter (:BF0000 in the plan).
select t1.*, t2.*
from filter_table ft
join table1 t1 on t1.sk = ft.sk
left outer join table2 t2 on t2.sk = ft.sk;
Be sure to gather statistics for all three tables! Often when the optimizer seems to be stupid it is because the statistics are missing or not up to date.
My table has no restrictions to deal with duplicate data. How can I achieve that, no same data is inserted into the table using 'sqlldr' utility? Do I have to make changes in the control file or in the parameters? or anything else?
You can't do it with sqlldr alone. One way is to remove duplicates after the load finishes.
To removing duplicates after sqlldr loads them:
DELETE FROM
table_name A
WHERE
a.rowid >
ANY (
SELECT
B.rowid
FROM
table_name B
WHERE
A.col1 = B.col1
AND
A.col2 = B.col2
);
Or you could use external tables for loading the data and just remove duplicates during the load using a query with distinct or group by clauses, or using a merge statement.
I have a table T1 in database D1 and table T2 in database D2. From T2 I need only those records whose primary keys are listed in T1.
The only way that I know so far is to use Merge Join (Inner Join). Since T2 contains much more records than T1 Merge Join would eliminate all records from T2 that don't exist in T1. Since this method is very slow is there any other method to do this task?
Thanks,
Ilija
Is there a reason the Lookup Transformation won't work?
Are D1 and D2 both on the same SQL Server instance? If so, the query is trivially easy to write:
SELECT t2.*
FROM D2.schema2.T2 t2
JOIN D1.schema1.T1 t1 ON t1.id = t2.id
(Obviously, you'd have to substitute the real names of the primary key column(s) in the join, as well as the schemas that T1 and T2 live under.)
Or you could make your data flow source be a query with the join rather than be a table.