two How do I UPDATE from a SELECT in SQL Server?
update table from another database sql server (24)
In SQL Server, it's possible to
insert into a table using a
INSERT INTO Table (col1, col2, col3) SELECT col1, col2, col3 FROM other_table WHERE sql = 'cool'
Is it also possible to update via a
SELECT? I have a temporary table containing the values, and would like to update another table using those values. Perhaps something like this:
UPDATE Table SET col1, col2 SELECT col1, col2 FROM other_table WHERE sql = 'cool' WHERE Table.id = other_table.id
CTE is more readable than the other answers here:
;WITH cte AS (SELECT col1,col2,id FROM other_table WHERE sql = 'cool') UPDATE A SET A.col1 = B.col1, A.col2 = B.col2 FROM table A INNER JOIN cte B ON A.id = B.id
declare @tblStudent table (id int,name varchar(300)) declare @tblMarks table (std_id int,std_name varchar(300),subject varchar(50),marks int) insert into @tblStudent Values (1,'Abdul') insert into @tblStudent Values(2,'Rahim') insert into @tblMarks Values(1,'','Math',50) insert into @tblMarks Values(1,'','History',40) insert into @tblMarks Values(2,'','Math',30) insert into @tblMarks Values(2,'','history',80) select * from @tblMarks update m set m.std_name=s.name from @tblMarks as m left join @tblStudent as s on s.id=m.std_id select * from @tblMarks
The simple way to do it is:
UPDATE table_to_update, table_info SET table_to_update.col1 = table_info.col1, table_to_update.col2 = table_info.col2 WHERE table_to_update.ID = table_info.ID
The other way to update from a select statement:
UPDATE A SET A.col = A.col,B.col1 = B.col1 FROM first_Table AS A INNER JOIN second_Table AS B ON A.id = B.id WHERE A.col2 = 'cool'
UPDATE table AS a INNER JOIN table2 AS b ON a.col1 = b.col1 INNER JOIN ... AS ... ON ... = ... SET ... WHERE ...
If you use MySQL instead of SQL Server, the syntax is:
UPDATE Table1 INNER JOIN Table2 ON Table1.id = Table2.id SET Table1.col1 = Table2.col1, Table1.col2 = Table2.col2
UPDATE t SET t.col1 = o.col1 FROM table1 AS t INNER JOIN table2 AS o ON t.id = o.id
This may be a niche reason to perform an update (for example, mainly used in a procedure), or may be obvious to others, but it should also be stated that you can perform an update-select statement without using join (in case the tables you're updating between have no common field).
update Table set Table.example = a.value from TableExample a where Table.field = *key value* -- finds the row in Table AND a.field = *key value* -- finds the row in TableExample a
Another possibility not mentioned yet is to just chuck the
SELECT statement itself into a CTE and then update the CTE.
;WITH CTE AS (SELECT T1.Col1, T2.Col1 AS _Col1, T1.Col2, T2.Col2 AS _Col2 FROM T1 JOIN T2 ON T1.id = T2.id /*Where clause added to exclude rows that are the same in both tables Handles NULL values correctly*/ WHERE EXISTS(SELECT T1.Col1, T1.Col2 EXCEPT SELECT T2.Col1, T2.Col2)) UPDATE CTE SET Col1 = _Col1, Col2 = _Col2
This has the benefit that it is easy to run the
SELECT statement on its own first to sanity check the results, but it does requires you to alias the columns as above if they are named the same in source and target tables.
This also has the same limitation as the proprietary
UPDATE ... FROM syntax shown in four of the other answers. If the source table is on the many side of a one-to-many join then it is undeterministic which of the possible matching joined records will be used in the
Update (an issue that
MERGE avoids by raising an error if there is an attempt to update the same row more than once).
Here is another useful syntax:
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);
It checks if it is null or not by using "WHERE EXIST".
You can use from this for update in sql server
UPDATE T1 SET T1.col1 = T2.col1, T1.col2 = T2.col2 FROM Table1 AS T1 INNER JOIN Table2 AS T2 ON T1.id = T2.id WHERE T1.col3 = 'cool'
If you are using SQL Server you can update one table from another without specifying a join and simply link the two from the
where clause. This makes a much simpler SQL query:
UPDATE Table1 SET Table1.col1 = Table2.col1, Table1.col2 = Table2.col2 FROM Table2 WHERE Table1.id = Table2.id
In the accepted answer, after the:
SET Table_A.col1 = Table_B.col1, Table_A.col2 = Table_B.col2
I would add:
OUTPUT deleted.*, inserted.*
What I usually do is putting everything in a roll backed transaction and using the
"OUTPUT": in this way I see everything that is about to happen. When I am happy with what I see, I change the
I usually need to document what I did, so I use the
"results to Text" option when I run the roll-backed query and I save both the script and the result of the OUTPUT. (Of course this is not practical if I changed too many rows)
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.
At first, I have created a table named with schoolold and inserted few records with respect to their column names and execute it.
Then I executed SELECT command to view inserted records.
Then I created a new table named with schoolnew and similarly executed above actions on it.
Then, to view inserted records in it, I execute SELECT command.
Now, Here I want to make some changes in third and fourth row, to complete this action, I execute UPDATE command with INNER JOIN.
To view the changes I execute the SELECT command.
You can see how Third and Fourth records of table schoolold easily replaced with table schoolnew by using INNER JOIN with UPDATE statement.
I add this only so you can see a quick way to write it so that you can check what will be updated before doing the update.
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 Table.id = other_table.id
For the record (and others searching like I was), you can do it in MySQL like this:
UPDATE first_table, second_table SET first_table.color = second_table.color WHERE first_table.id = second_table.foreign_id
Consolidating all the different approaches here.
- Select update
- Update with a common table expression
Sample table structure are below and will update from Product_BAK to Product table.
CREATE TABLE [dbo].[Product]( [Id] [int] IDENTITY(1, 1) NOT NULL, [Name] [nvarchar](100) NOT NULL, [Description] [nvarchar](100) NULL ) ON [PRIMARY]
CREATE TABLE [dbo].[Product_BAK]( [Id] [int] IDENTITY(1, 1) NOT NULL, [Name] [nvarchar](100) NOT NULL, [Description] [nvarchar](100) NULL ) ON [PRIMARY]
1. Select update
update P1 set Name = P2.Name from Product P1 inner join Product_Bak P2 on p1.id = P2.id where p1.id = 2
2. Update with a common table expression
; With CTE as ( select id, name from Product_Bak where id = 2 ) update P set Name = P2.name from product P inner join CTE P2 on P.id = P2.id where P2.id = 2
Merge into product P1 using Product_Bak P2 on P1.id = P2.id when matched then update set p1.[description] = p2.[description], p1.name = P2.Name;
In the Merge statement, we can do inset if not finding a matching record in the target, but exist in the source and please find the syntax:
Merge into product P1 using Product_Bak P2 on P1.id = P2.id when matched then update set p1.[description] = p2.[description], p1.name = P2.Name WHEN NOT MATCHED THEN insert (name, description) values(p2.name, P2.description);
UPDATE table SET Col1 = i.Col1, Col2 = i.Col2 FROM ( SELECT ID, Col1, Col2 FROM other_table) i WHERE i.ID = table.ID
UPDATE t SET t.col1 = o.col1, t.col2 = o.col2 FROM other_table o JOIN t ON t.id = o.id WHERE o.sql = 'cool'
The other way is to use a derived table:
UPDATE t SET t.col1 = a.col1 ,t.col2 = a.col2 FROM ( SELECT id, col1, col2 FROM @tbl2) a INNER JOIN @tbl1 t ON t.id = a.id
DECLARE @tbl1 TABLE (id INT, col1 VARCHAR(10), col2 VARCHAR(10)) DECLARE @tbl2 TABLE (id INT, col1 VARCHAR(10), col2 VARCHAR(10)) INSERT @tbl1 SELECT 1, 'a', 'b' UNION SELECT 2, 'b', 'c' INSERT @tbl2 SELECT 1, '1', '2' UNION SELECT 2, '3', '4' UPDATE t SET t.col1 = a.col1 ,t.col2 = a.col2 FROM ( SELECT id, col1, col2 FROM @tbl2) a INNER JOIN @tbl1 t ON t.id = a.id SELECT * FROM @tbl1 SELECT * FROM @tbl2
I'd modify Robin's excellent answer to the following:
UPDATE Table SET Table.col1 = other_table.col1, Table.col2 = other_table.col2 FROM Table INNER JOIN other_table ON Table.id = other_table.id WHERE Table.col1 != other_table.col1 OR Table.col2 != 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 )
Without a WHERE clause, you'll affect even rows that don't need to be affected, which could (possibly) cause index recalculation or fire triggers that really shouldn't have been fired.
In SQL Server 2008 (or better), use
MERGE INTO YourTable T USING other_table S ON T.id = S.id AND S.tsql = 'cool' WHEN MATCHED THEN UPDATE SET col1 = S.col1, col2 = S.col2;
MERGE INTO YourTable T USING ( SELECT id, col1, col2 FROM other_table WHERE tsql = 'cool' ) S ON T.id = S.id WHEN MATCHED THEN UPDATE SET col1 = S.col1, col2 = S.col2;
UPDATE Table_A SET Table_A.col1 = Table_B.col1, Table_A.col2 = Table_B.col2 FROM Some_Table AS Table_A INNER JOIN Other_Table AS Table_B ON Table_A.id = Table_B.id WHERE Table_A.col3 = 'cool'
And if you wanted to join the table with itself (which won't happen too often):
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 .................. -- the join clause is whatever suits you