How can I update a complete data row by using a data row from another table.
Example:
Table A
ID | NAME | ... |
----------------------------
1 | Test | ... |
2 | Test2 | ... |
Table B
ID | NAME | ... |
----------------------------
1 | Test97 | ... |
So I want to copy the content of a single row of Table B to Table A and override existing values. I do not want to name all columns. The contents of table A and B are redundant.
Summarize:
I want an equivalent to the following INSERT Statement as an UPDATE Statement:
INSERT INTO destTable
VALUES (SELECT * FROM TABLE2)
FROM srcTable
Any hint, even telling me that its not possible, is very appricated.
you can update a set of columns (you still have to list the columns once):
SQL> UPDATE table_a
2 SET (ID, NAME, etc)
3 = (SELECT * FROM table_b WHERE table_b.id = table_a.id)
4 WHERE table_a.id IN (SELECT ID FROM table_b);
1 row updated
Like so:
UPDATE suppliers
SET supplier_name = ( SELECT customers.name
FROM customers
WHERE customers.customer_id = suppliers.supplier_id)
WHERE EXISTS
( SELECT customers.name
FROM customers
WHERE customers.customer_id = suppliers.supplier_id);
You want to use an Oracle MERGE statement. With this statement, it inserts if a match doesn't exist and updates if it already exists.
Here is a site with an example.
MERGE INTO bonuses b
USING (
SELECT employee_id, salary, dept_no
FROM employee
WHERE dept_no =20) e
ON (b.employee_id = e.employee_id)
WHEN MATCHED THEN
UPDATE SET b.bonus = e.salary * 0.1
DELETE WHERE (e.salary < 40000)
WHEN NOT MATCHED THEN
INSERT (b.employee_id, b.bonus)
VALUES (e.employee_id, e.salary * 0.05)
WHERE (e.salary > 40000);
Related
I have two tables. One (let's call it table1) looks a bit like this:
account_number | offer_code
---------------|-----------
1 | 123
1 | 456
2 | 123
The other table (let's call it table2) looks a bit like this:
account_number | offer_code
---------------|-----------
1 | 123
I want to delete all rows from table1 where the account_number AND the offer_code match a row in table2. So afterwards table1 would look like this:
account_number | offer_code
---------------|-----------
1 | 456
2 | 123
I've tried the following, but it doesn't run:
DELETE
FROM TABLE1 A
INNER JOIN
TABLE2 B
ON A.ACCOUNT_NUMBER = B.ACCOUNT_NUMBER
AND A.OFFER_CODE = B.OFFER_CODE
;
I've also tried the following. It seems to run, but the sheer volume of data in both tables (65.5m rows in table1 and 9m in table2) mean it takes an impractically long time to do so (I was forced to kill the query after 3 hours).
DELETE
FROM TABLE1
WHERE CONCAT(ACCOUNT_NUMBER, OFFER_CODE) IN
(
SELECT CONCAT(ACCOUNT_NUMBER, OFFER_CODE)
FROM TABLE2
)
;
Does anyone know if there is a way to accomplish this efficiently please?
Databases do not like update and delete processes. They are exhausting. Depending on your application(carefully check this out!!!) you can try this:
create table table1_tmp
select * from table1
minus
select * from table2;
alter table table1 rename to table1_tmp2;
alter table table1_tmp rename to table1;
Trying to compare between two columns and check if there are no records that exist with the reversal between those two columns. Other Words looking for instances where 1-> 3 exists but 3->1 does not exist. If 1->2 and 2->1 exists we will still consider 1 to be part of the results.
Table = Betweens
start_id | end_id
1 | 2
2 | 1
1 | 3
1 would be added since it is a start to an end with no opposite present of 3,1. Though it did not get added until the 3rd entry since 1 and 2 had an opposite.
So, eventually it will just return names where the reversal does not exist.
I then want to join another table where the number from the previous problem has its name installed on it.
Table = Names
id | name
1 | Mars
2 | Earth
3 | Jupiter
So results will just be the names of those that don't have an opposite.
You can use a not exists condition:
select t1.start_id, t1.end_id
from the_table t1
where not exists (select *
from the_table t2
where t2.end_id = t1.start_id
and t2.start_id = t1.end_id);
I'm not sure about your data volume, so with your ask, below query will supply desired result for you in Sql Server.
create table TableBetweens
(start_id INT,
end_id INT
)
INSERT INTO TableBetweens VALUES(1,2)
INSERT INTO TableBetweens VALUES(2,1)
INSERT INTO TableBetweens VALUES(1,3)
create table TableNames
(id INT,
NAME VARCHAR(50)
)
INSERT INTO TableNames VALUES(1,'Mars')
INSERT INTO TableNames VALUES(2,'Earth')
INSERT INTO TableNames VALUES(3,'Jupiter')
SELECT *
FROM TableNames c
WHERE c.id IN (
SELECT nameid1.nameid
FROM (SELECT a.start_id, a.end_id
FROM TableBetweens a
LEFT JOIN TableBetweens b
ON CONCAT(a.start_id,a.end_id) = CONCAT(b.end_id,b.start_id)
WHERE b.end_id IS NULL
AND b.start_id IS NULL) filterData
UNPIVOT
(
nameid
FOR id IN (filterData.start_id,filterData.end_id)
) AS nameid1
)
i have an example table like this named a.
A_ID |B_ID |C_ID |NUMBER |REFERENCE |
----------------------------------------------------------------------------------------
3-14SW-958 |3-13M7-3271 |3-16XW-3623 |02220537890 |131165138672 |
3-14SW-958 |3-152G-1599 |3-15NH-3456 |02220537890 |131165138672 |
3-14MW-2720 |3-14V0-3580 |3-15IE-2736 |02287528203 |131183102805 |
3-14MW-2720 |3-16LT-2845 |3-13WH-3111 |02287528203 |131183102805 |
3-14SW-958 |3-152G-1599 |3-15NH-3456 |131165138672|02220537890 |
3-14MW-2720 |3-14V0-3580 |3-15IE-2736 |131183102805|02287528203 |
Within this table, i want result that the number are referenced but has different values B_ID and C_ID like this
|B_ID |C_ID |NUMBER |REFERENCE |
|3-13M7-3271 |3-16XW-3623 |02220537890 |131165138672 |
|3-16LT-2845 |3-13WH-3111 |02287528203 |131183102805 |
How would you express this in a SQL query? I was thinking self join but i still cant get it
this is what i mean referenced
|NUMBER |REFERENCE |COUNT(*)|
|02220537890 |131165138672 |2 |
|131165138672|02220537890 |1 |
using max or min function wont get it
Many thanks in advance
You need to use the GROUP BY and HAVING as follows:
SELECT MAX(B_ID) AS B_ID,
MAX(C_ID) AS C_ID,
NUMBER,
REFERENCE
FROM YOUR_TABLE
GROUP BY A_ID, NUMBER, REFERENCE
HAVING COUNT(1) > 1;
Note: Avoid using the oracle reserved keywords as the name of the columns (In you case, NUMBER and REFERENCE should be avoided as the column names)
try this:
select b_id, c_id, n, r from tmp_test where b_id in (
select max(b_id) from tmp_test group by n having count(1)>1
);
to extract unique NUMBERs and REFs:
select n, r from tmp_test group by n, r having count(1)>1
Within this table, i want result that the number are referenced but has different values B_ID and C_ID like this
You can use EXISTS :
SELECT t.*
FROM table t
WHERE EXISTS (SELECT 1 FROM table t1 WHERE t1.refrence = t.refrence AND t1.b_id <> t.b_id);
Is it what you're looking for?
SQL
SELECT a.B_ID , a.C_ID ,a.`NUMBER` ,a.REFERENCE FROM Test a
INNER JOIN Test b
on a.REFERENCE = b.REFERENCE
AND a.B_ID != b.B_ID
AND a.C_ID !=b.C_ID
OUTPUT
B_ID |C_ID |NUMBER |REFERENCE |
-----------|-----------|----------|------------|
3-152G-1599|3-15NH-3456|2220537890|131165138672|
3-13M7-3271|3-16XW-3623|2220537890|131165138672|
3-16LT-2845|3-13WH-3111|2287528203|131183102805|
3-14V0-3580|3-15IE-2736|2287528203|131183102805|
I think this requirement is rarely encountered so I couldn't search for similar questions.
I have a table that needs to update the ID. For example ID 123 in table1 is actually supposed to be 456. I have a separate reference table built that stores the mapping (e.g. old 123 maps to new id 456).
I used the below query but apparently it returned error 38104, columns referenced in the ON clause cannot be updated.
MERGE INTO table1
USING ref_table ON (table1.ID = ref_table.ID_Old)
WHEN MATCHED THEN UPDATE SET table.ID = ref_table.ID_New;
Is there other way to achieve my purpose?
Thanks and much appreciated for your answer!
Use the ROWID pseudocolumn:
SQL Fiddle
Oracle 11g R2 Schema Setup:
CREATE TABLE TABLE1( ID ) AS
SELECT 1 FROM DUAL UNION ALL
SELECT 2 FROM DUAL UNION ALL
SELECT 3 FROM DUAL;
CREATE TABLE REF_TABLE( ID_OLD, ID_NEW ) AS
SELECT 1, 4 FROM DUAL UNION ALL
SELECT 2, 5 FROM DUAL;
MERGE INTO TABLE1 dst
USING ( SELECT t.ROWID AS rid,
r.id_new
FROM TABLE1 t
INNER JOIN REF_TABLE r
ON ( t.id = r.id_old ) ) src
ON ( dst.ROWID = src.RID )
WHEN MATCHED THEN
UPDATE SET id = src.id_new;
Query 1:
SELECT * FROM table1
Results:
| ID |
|----|
| 4 |
| 5 |
| 3 |
You can't update a column used in the ON clause in a MERGE. But if you don't need to make other changes that MERGE allows like WHEN NOT MATCHED or deleting, etc. you can just use a UPDATE to achieve this.
You mentioned this is an ID that needs an update. Here's an example using a scalar subquery. As it is an ID, this presumes UNIQUE ID_OLD values in REF_TABLE. I wasn't sure if Every row needs an update or only a sub-set, so set the update here to only update rows that have a value in REF_TABLE.
CREATE TABLE TABLE1(
ID NUMBER
);
CREATE TABLE REF_TABLE(
ID_OLD NUMBER,
ID_NEW NUMBER
);
INSERT INTO TABLE1 VALUES (1);
INSERT INTO TABLE1 VALUES (2);
INSERT INTO TABLE1 VALUES (100);
INSERT INTO REF_TABLE VALUES (1,10);
INSERT INTO REF_TABLE VALUES (2,20);
Initial State:
SELECT * FROM TABLE1;
ID
1
2
100
Then make the UPDATE
UPDATE TABLE1
SET TABLE1.ID = (SELECT REF_TABLE.ID_NEW
FROM REF_TABLE
WHERE REF_TABLE.ID_OLD = ID)
WHERE TABLE1.ID IN (SELECT REF_TABLE.ID_OLD
FROM REF_TABLE);
2 rows updated.
And check the change:
SELECT * FROM TABLE1;
ID
10
20
100
Setup:
create table main(id integer unsigned);
create table test1(id integer unsigned);
create table test2(id integer unsigned);
insert into main(id) value(1);
insert into test1(id) value(1);
insert into test1(id) value(1);
insert into test2(id) value(1);
insert into test2(id) value(1);
insert into test2(id) value(1);
Using:
select main.id,
count(test1.id),
count(test2.id)
from main
left join test1 on main.id=test1.id
left join test2 on main.id=test2.id
group by main.id;
...returns:
+------+-----------------+-----------------+
| id | count(test1.id) | count(test2.id) |
+------+-----------------+-----------------+
| 1 | 6 | 6 |
+------+-----------------+-----------------+
How to get the desired result of 1 2 3?
EDIT
The solution should be extensible,I'm going to query multiple count() information about main.id in the future.
Not optimal, but works:
select
count(*),
(select count(*) from test1 where test1.id = main.id) as test1_count,
(select count(*) from test2 where test2.id = main.id) as test2_count
from main
You created tables that contain the following:
Table main
id
----
1
Table test1
id
----
1
1
Table test2
id
----
1
1
1
When you join this like you do you will get the following
id id id
-----------
1 1 1
1 1 1
1 1 1
1 1 1
1 1 1
1 1 1
So how should SQL answer differently?
You can call:
SELECT id,COUNT(id) FROM main GROUP BY id
for every table, then join them by id.
Not sure if this works in MySQL exactly as written (I'm using Oracle):
1 select main.id, t1.rowcount, t2.rowcount
2 from main
3 left join (select id,count(*) rowcount from test1 group by id) t1
4 on t1.id = main.id
5 left join (select id,count(*) rowcount from test2 group by id) t2
6* on t2.id = main.id
SQL> /
ID ROWCOUNT ROWCOUNT
1 2 3
You're inadvertently creating a Cartesian product between test1 and test2, so every matching row in test1 is combined with every matching row in test2. The result of both counts, therefore, is the count of matching rows in test1 multiplied by the count of matching rows in test2.
This is a common SQL antipattern. A lot of people have this problem, because they think they have to get both counts in a single query.
Some other folks on this thread have suggested ways of compensating for the Cartesian product through creative use of subqueries, but the solution is simply to run two separate queries:
select main.id, count(test1.id)
from main
left join test1 on main.id=test1.id
group by main.id;
select main.id, count(test2.id)
from main
left join test2 on main.id=test2.id
group by main.id;
You don't have to do every task in a single SQL query! Frequently it's easier to code -- and easier for the RDBMS to execute -- multiple simpler queries.
You can get the desired result by using:
SELECT COUNT(*) as main_count,
(SELECT COUNT(*) FROM table1) as table1Count,
(SELECT COUNT(*) from table2) as table2Count FROM main