This can also be used to change the column to NULL if the column has no default and is defined to allow null values.
Compound assignment operator: = Add and assign -= Subtract and assign *= Multiply and assign /= Divide and assign %= Modulo and assign &= Bitwise AND and assign ^= Bitwise XOR and assign |= Bitwise OR and assign Returns updated data or expressions based on it as part of the UPDATE operation.
Common table expressions can also be used with the SELECT, INSERT, DELETE, and CREATE VIEW statements.
For more information, see WITH common_table_expression (Transact-SQL). For information about table hints, see Table Hints (Transact-SQL).
Orders AS O GROUP BY O.customer_id )OA ON C.customer_id = OA.customer_id; table while pulling in necessary information from other table(s) referenced in the statement.
Before I show you the multi-table solution, let me demonstrate the simplest form of the --UPDATE C SET /* SELECT *, -- */ order_count = FROM dbo.
Somewhat related, I often like to write my UPDATE queries as SELECT statements first so that I can see the data that will be updated before I execute. This also has the same limitation as the proprietary Thank you!
Sebastian covers a technique for this in a recent blog post: sqlity.net/en/2867/update-from-select This will tend to work across almost all DBMS which means learn once, execute everywhere. Col2 AS _Col2 FROM T1 JOIN T2 ON T1= T2/*Where clause added to exclude rows that are the same in both tables Handles NULL values correctly*/ WHERE EXISTS(SELECT T1. I know this is old, but just wanted to say this one worked for me.
If that is more important to you than performance you might prefer this answer, especially if your update is a one off to correct some data. My server wont allow FROM to be used in an UPDATE statement. 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.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 ..................
-- 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.