I need to update this table in SQL Server with data from its 'parent' table, see below:
Table: sale
id (int)
udid (int)
assid (int)
Table: ud
id (int)
assid (int)
sale.assid
contains the correct value to update ud.assid
.
What query will do this? I'm thinking of a join
but I'm not sure if it's possible.
Syntax strictly depends on which SQL DBMS you're using. Here are some ways to do it in ANSI/ISO (aka should work on any SQL DBMS), MySQL, SQL Server, and Oracle. Be advised that my suggested ANSI/ISO method will typically be much slower than the other two methods, but if you're using a SQL DBMS other than MySQL, SQL Server, or Oracle, then it may be the only way to go (e.g. if your SQL DBMS doesn't support MERGE
):
ANSI/ISO:
update ud
set assid = (
select sale.assid
from sale
where sale.udid = ud.id
)
where exists (
select *
from sale
where sale.udid = ud.id
);
MySQL:
update ud u
inner join sale s on
u.id = s.udid
set u.assid = s.assid
SQL Server:
update u
set u.assid = s.assid
from ud u
inner join sale s on
u.id = s.udid
PostgreSQL:
update ud
set assid = s.assid
from sale s
where ud.id = s.udid;
Note that the target table must not be repeated in the FROM
clause for Postgres.
Oracle:
update
(select
u.assid as new_assid,
s.assid as old_assid
from ud u
inner join sale s on
u.id = s.udid) up
set up.new_assid = up.old_assid
SQLite:
update ud
set assid = (
select sale.assid
from sale
where sale.udid = ud.id
)
where RowID in (
select RowID
from ud
where sale.udid = ud.id
);
This should work in SQL Server:
update ud
set assid = sale.assid
from sale
where sale.udid = id
postgres
UPDATE table1
SET COLUMN = value
FROM table2,
table3
WHERE table1.column_id = table2.id
AND table1.column_id = table3.id
AND table1.COLUMN = value
AND table2.COLUMN = value
AND table3.COLUMN = value
A standard SQL approach would be
UPDATE ud
SET assid = (SELECT assid FROM sale s WHERE ud.id=s.id)
On SQL Server you can use a join
UPDATE ud
SET assid = s.assid
FROM ud u
JOIN sale s ON u.id=s.id
CREATE TABLE ud (id integer, assid integer);
CREATE TABLE sales (id integer, udid integer, assid integer);
UPDATE ud
SET assid = sales.assid
FROM sales
WHERE sales.id = ud.id;
Simplified update query using JOIN-ing multiple tables.
UPDATE
first_table ft
JOIN second_table st ON st.some_id = ft.some_id
JOIN third_table tt ON tt.some_id = st.some_id
.....
SET
ft.some_column = some_value
WHERE ft.some_column = 123456 AND st.some_column = 123456
Note - first_table, second_table, third_table and some_column like 123456 are demo table names, column names and ids. Replace them with the valid names.
Another example why SQL isn't really portable.
For MySQL it would be:
update ud, sale
set ud.assid = sale.assid
where sale.udid = ud.id;
For more info read multiple table update: http://dev.mysql.com/doc/refman/5.0/en/update.html
UPDATE [LOW_PRIORITY] [IGNORE] table_references
SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
[WHERE where_condition]
Teradata Aster offers another interesting way how to achieve the goal:
MERGE INTO ud --what table should be updated
USING sale -- from what table/relation update info should be taken
ON ud.id = sale.udid --join condition
WHEN MATCHED THEN
UPDATE SET ud.assid = sale.assid; -- how to update
I was thinking the SQL-Server one in the top post would work for Sybase since they are both T-SQL but unfortunately not.
For Sybase I found the update needs to be on the table itself not the alias:
update ud
set u.assid = s.assid
from ud u
inner join sale s on
u.id = s.udid
MySQL
You'll get the best performance if you forget the where clause and place all conditions in the ON expression.
I think this is because the query first has to join the tables then runs the where clause on that, so if you can reduce what is required to join then that's the fasted way to get the results/do the udpate.
Example
Scenario
You have a table of users. They can log in using their username or email or account_number. These accounts can be active (1) or inactive (0). This table has 50000 rows
You then have a table of users to disable at one go because you find out they've all done something bad. This table however, has one column with usernames, emails and account numbers mixed. It also has a "has_run" indicator which needs to be set to 1 (true) when it has been run
Query
UPDATE users User
INNER JOIN
blacklist_users BlacklistUser
ON
(
User.username = BlacklistUser.account_ref
OR
User.email = BlacklistedUser.account_ref
OR
User.phone_number = BlacklistUser.account_ref
AND
User.is_active = 1
AND
BlacklistUser.has_run = 0
)
SET
User.is_active = 0,
BlacklistUser.has_run = 1;
Reasoning
If we had to join on just the OR conditions it would essentially need to check each row 4 times to see if it should join, and potentially return a lot more rows. However, by giving it more conditions it can "skip" a lot of rows if they don't meet all the conditions when joining.
Bonus
It's more readable. All the conditions are in one place and the rows to update are in one place
The following statement with FROM keyword is used to update multiple rows with a join
UPDATE users
set users.DivisionId=divisions.DivisionId
from divisions join users on divisions.Name=users.Division
The simplest way is to use the Common Table Expression (CTE) introduced in SQL 2005
with cte as
(select u.assid col1 ,s.assid col2 from ud u inner join sale s on u.id = s.udid)
update cte set col1=col2
And in MS ACCESS:
UPDATE ud
INNER JOIN sale ON ud.id = sale.udid
SET ud.assid = sale.assid;
Try this one, I think this will works for you
update ud
set ud.assid = sale.assid
from ud
Inner join sale on ud.id = sale.udid
where sale.udid is not null
UPDATE tblAppraisalBasicData
SET tblAppraisalBasicData.ISCbo=1
FROM tblAppraisalBasicData SI INNER JOIN aaa_test RAN ON SI.EmpID = RAN.ID
For SQLite use the RowID property to make the update:
update Table set column = 'NewValue'
where RowID =
(select t1.RowID from Table t1
join Table2 t2 on t1.JoinField = t2.JoinField
where t2.SelectValue = 'FooMyBarPlease');
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CAPITALIZED
SQL keywords orlowercase
(like here)? (Or does it not matter)