Sql updating a row
Also make sure you have indexes, especially if you have a WHERE clause on the SELECT statement.
A filtered index worked great for me as I was filtering based on payment statuses. Paid Order Index IS NOT NULL -- test to 'break' some of the rows, and then run the UPDATE again update [order] set Paid Order Index = 2 where Paid Order Index=3 When I say the performance increase was massive I mean it was essentially instantaneous when updating a small number of rows.
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@Craig: What do you mean by "two variables named x"?
This UPDATE statement isn't referencing any variables.
The WHERE clause specifies which record(s) that should be updated.
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UPDATE Table SET Table.col1 = other_table.col1, Table.col2 = other_table.col2 FROM Table INNER JOIN other_table ON = other_WHERE Table.col1 ! = other_table.col2 or (other_table.col1 is not null and table.col1 is null) or (other_table.col2 is not null and table.col2 is null) ; WITH CTE AS (SELECT T1. So all the answers involving the FROM clause returned a syntax error. UPDATE suppliers SET supplier_name = (SELECT FROM customers WHERE customers.customer_id = suppliers.supplier_id) WHERE EXISTS (SELECT FROM customers WHERE customers.customer_id = suppliers.supplier_id); UPDATE Table SET Table.col1 = other_table.col1, Table.col2 = other_table.col2 --select Table.col1, other_table.col, Table.col2,other_table.col2, * FROM Table INNER JOIN other_table ON = other_update t1 -- just reference table alias here set t1.somevalue = t2.somevalue from table1 t1 -- these rows will be the targets inner join table1 t2 -- these rows will be used as source on ..................
There's only one thing named x in this solution and it's the derived table defined in the FROM clause. Maybe the syntax is unfamiliar to you, but that's all right, you can just explain what you consider confusing about it and hopefully get a response clearing up your confusion (in case the manual doesn't help).
With Update Data As ( SELECT RS_NOM, ROW_NUMBER() OVER (ORDER BY [RS_NOM] DESC) AS RN FROM DESTINATAIRE_TEMP ) UPDATE DESTINATAIRE_TEMP SET CODE_DEST = RN FROM DESTINATAIRE_TEMP INNER JOIN Update Data ON DESTINATAIRE_TEMP. RS_NOM By adding a WHERE clause I found the performance improved massively for subsequent updates.
-- the join clause is whatever suits you UPDATE from SELECT with INNER JOIN in SQL Database Since there are too many replies of this post, which are most heavily up-voted, I thought I would provide my suggestion here too.
Although the question is very interesting, I have seen in many forum sites and made a solution using INNER JOIN with screenshots.