I have two tables:
Table1:
column1|column2|column3|column4|column5
---------------------------------------
'test1'| null | 12 |'old1' | 'gr1'
'test1'| 123 | null |'old2' | 'gr2'
'test2'| 488 | null |'old3' | 'gr3'
'test3'| 488 | null |'old4' | 'gr4'
Table2: (it's a SELECT query)
column1|column2|column4|column5
-------------------------------
'test1'| 999 | 'new1'| 'gr2'
'test3'| 1355 | 'new4'| 'gr4'
I have created the second table as a query in order to update the values of the first, where the key of the first table is (column1, column5). So the table I am after is:
Table1:
column1|column2|column3|column4|column5
---------------------------------------
'test1'| null | 12 |'old1' | 'gr1'
'test1'| 999 | null |'new1' | 'gr2'
'test2'| 488 | null |'old3' | 'gr3'
'test3'| 1355 | null |'new4' | 'gr4'
How is this done?
The exakt SQL command will of course depend on the query which produces your second table. Assuming, this query would just be "SELECT * FROM yourtable2", you can do following update command to achieve your goal:
UPDATE yourtable
SET
column2 = x.column2,
column4 = x.column4
FROM (SELECT * FROM yourtable2) x
WHERE yourtable.column1 = x.column1
AND yourtable.column5 = x.column5
Here you see this is working (in case the table "yourtable2" provides the correct data): db<>fiddle
So, you can replace the "SELECT FROM yourtable2" by your query and it will work.
Can you try
UPDATE table1 t1 set (column2,column4) = (
SELECT column2,column4
FROM table2 t2
WHERE t1.column1 = t2.column1 and t1.column5 = t2.column5
)
If you have table2 as a query, you can use WITH
WITH table2 (column1,column2,column4,column5) AS (
<your select query>
),
UPDATE table1 t1 set (column2,column4) = (
SELECT column2,column4
FROM table2 t2
WHERE t1.column1 = t2.column1 and t1.column5 = t2.column5
)
Related
I want to take the data from two tables and output them in one row .
output will have two columns "to" and "from" where the condition is "from" will be having data from second table where type is true and "to" column will have data from second table where type is false . FK_ID in second table is linked to ID on the first table . Please help with the query.
I was trying to do with inner joins and union was not able to make it work . Thanks in advance .
TABLE 1
ID | PATH|
1 | ABC |
2 | EFG |
TABLE 2
ID | FK_ID | NUMBER | TYPE
20 | 1 | 123 | TRUE
21 | 1 | 456 | FALSE
28 | 2 | 888 | FALSE
29 | 2 | 939 | TRUE
OUTPUT SHOULD BE:
ID | PATH | TO | FROM
1 | ABC | 456 | 123
2 | EFG | 888 | 939
Use aggregation with pivoting logic to identify the "to" and "from" components of each path:
SELECT
t1.ID,
t1.PATH,
MAX(CASE WHEN t2.TYPE = 'FALSE' THEN t2.NUMBER END) AS "TO",
MAX(CASE WHEN t2.TYPE = 'TRUE' THEN t2.NUMBER END) AS "FROM"
FROM table1 t1
LEFT JOIN table2 t2
ON t1.ID = t2.FK_ID
GROUP BY
t1.ID,
t1.PATH
ORDER BY
t1.ID;
If performance is an issue, you might find a lateral join to be faster:
SELECT t1.*, t2.*
FROM table1 t1 LEFT JOIN LATERAL
(SELECT SUM(T2.NUMBER) FILTER (WHERE NOT t2.TYPE) as num_to,
SUM(T2.NUMBER) FILTER (WHERE t2.TYPE) as num_from
FROM table2 t2
WHERE t1.ID = t2.FK_ID
) t2
ORDER BY t1.ID;
This avoids the outer GROUP BY and probably the sorting as well (assuming that ID is the primary key).
It also assumes that TYPE is a Postgres boolean type. If not, use string comparisons for the WHERE clauses.
I have two tables:
TABLE1
id_attr
-------
1
2
3
TABLE2
id | id_attr | val
----------------------
10 | 1 | A
10 | 2 | B
As a result I want a table that show:
RESULT
id | id_attr | val
----------------------
10 | 1 | A
10 | 2 | B
10 | 3 | NULL
So I want the row with id=10 and id_attr=3 also when id_Attr=3 is missing in TABLE2 (and I know that because I have a NULL value (or something else) in the val column of RESULT.
NB: I could have others ids in table2. For example, after insert this row on table2: {11,1,A}, as RESULT I want:
id | id_attr | val
----------------------
10 | 1 | A
10 | 2 | B
10 | 3 | NULL
11 | 1 | A
11 | 2 | NULL
11 | 3 | NULL
So, for every id, I want always the match with all id_attr.
Your specific example only has one id, so you can use the following:
select t2.id, t2.id_attr, t2.val
from table2 t2
union all
select 10, t1.id_attr, NULL
from table1 t1
where not exists (select 1 from table2 t2 where t2.id_attr = t1.id_attr);
EDIT:
You can get all combinations of attributes and ids in the following way. Use a cross join to create all the rows you want and then a left join to bring in the data you want:
select i.id, t1.id_attr, t2.val
from (select distinct id from table2) i cross join
table1 t1 left join
table2 t2
on t2.id = i.id and t2.id_attr = t1.id_attr;
It sounds like you want to do just an outer join on id_attr instead of id.
select * from table2 t2
left outer join table1 t1 on t2.id_attr = t1.id_attr;
I need to update the column data based on matching record found in both Table.
I want to update the record of NAME column from TABLE2
Following are the tables
Table1
---------------
Id | Name | color
1 | abc | red
2 | def | green
3 | ghi | blue
Table2
---------------
Id | Name | color |fiedId
1 | abc | red | 1
2 | def | green | 1
3 | ghi | blue | 2
Here table1 ID column is the Foreign Key in table2 as fieldId.
So, I want to update all the record which fall under this condition
table1.id = table2.fieldId
Yet another option, using MERGE:
merge into table2 t2
using (select id, name from table1) x
on (t2.fieldid = x.id)
when matched then update set
t2.name = x.name;
Or, for setting the name to 'xxx':
merge into table2 t2
using (select id from table1) x
on (t2.fiedid = x.id)
when matched then update set
t2.name = 'xxx';
Sounds like you just want an update like this:
update table2 t2
set t2.name =
( select t1.name
from table1 t1
where t1.id = t2.fieldid )
Regarding the followup question:
what if i want to set Name = "xxx" for all matching rows?
update table2 t2
set t2.name = 'xxx'
where t2.fieldid in
( select t1.id from table1 t1 )
or this can be written as:
update table2 t2
set t2.name = 'xxx'
where exists
( select null from table1 t1
where t1.id = t2.fieldid )
I am wondering what should I use in SQL Server 2016 or 2017 (CTE, LOOP, JOINS, CURSOR, REPLACE, etc) to match (replace) every value in every row in temp table? What is the best solution from performance perspective?
Source Table
|id |id2|
| 1 | 2 |
| 2 | 1 |
| 1 | 1 |
| 2 | 2 |
Mapping Table
|id |newid|
| 1 | 3 |
| 2 | 4 |
Expected result
|id |id2|
| 3 | 4 |
| 4 | 3 |
| 3 | 3 |
| 4 | 4 |
You may join the second table to the first table twice:
WITH cte AS (
SELECT
t1.id AS id_old,
t1.id2 AS id2_old,
t2a.newid AS id_new,
t2b.newid AS id2_new
FROM table1 t1
LEFT JOIN table2 t2a
ON t1.id = t2a.id
LEFT JOIN table2 t2b
ON t1.id2 = t2b.id
)
UPDATE cte
SET
id_old = id_new,
id2_old = id2_new;
Demo
Not sure if you want just a select here, or maybe an update, or an insert into another table. In any case, the core logic I gave above should work for all these cases.
You'd need to apply joins on update query. Something like this:
Update tblA set column1 = 'something', column2 = 'something'
from actualName tblA
inner join MappingTable tblB
on tblA.ID = tblB.ID
this query will compare eachrow with ids and if matched then it will update/replace the value of the column as you desire. :)
Do the self join only
SELECT t1.id2 as id, t2.id2
FROM table1 t
INNER JOIN table2 t1 on t1.id = t.id
INNER JOIN table2 t2 on t2.id = t.id2
This may have best performance from solutions posted here if you have indexes set appropriately:
select (select [newid] from MappingTable where id = [ST].[id]) [id],
(select [newid] from MappingTable where id = [ST].[id2]) [id2]
from SourecTable [ST]
What is the most clever way to delete tuples from table1, that are in the second table,
if the second table is not a part of initial database, but a result of some really big query?
table1 *this table is a result of some query
------------- -------------
| id1 | id2 | | id1 | id2 |
------------- -------------
| 1 2 | | 5 6 |
| 3 4 | | 1 2 |
| 5 6 | | 11 12 |
| 7 8 | -------------
| 9 10 |
| 11 12 |
| 13 14 |
-------------
I came up with
delete from table1
where id1 in (select id1 from ( really long query to get a second table))
and id2 in (select id2 from (the same really long query to get a second table));
It works, but I feel like I'm doing it way too wrong, and not keeping the query DRY.
And would the way you suggest work the same if table1 had an additional column, for example "somecol"?
IMO, You can use EXISTS statement like this:
DELETE FROM table1
WHERE EXISTS (
SELECT 1
FROM (<your long query>) AS dt
WHERE table1.id1 = dt.id1
AND table1.id2 = dt.id2);
[SQL Fiddle Sample]
One method is to use with, delete and exists:
with secondtable as (
<your query here>
)
delete from table1
where exists (select 1
from secondtable st
where table1.id1 = st.id1 and table1.id2 = st.id2
);
A Correlated Subquery using EXISTS allows matching multiple columns:
delete
from table1
where exists
( select * from
(
"really long query"
) as t2
where table1.id1 = t2.id1 -- correlating inner and outer table
and table1.id2 = t2.id2 -- similar to a join-condition
)