If you see anything in the documentation that is not correct, does not match your experience with the particular feature or requires further clarification, please use this form to report a documentation issue. In some databases, such as Postgre SQL, when a FROM clause is present, what essentially happens is that the target table is joined to the tables mentioned in the fromlist, and each output row of the join represents an update operation for the target table.New Value Else employee Table.lastname End, address = CASE When(employee Table.address ='N' and ID=30) THEN Value Table.
clause allows you to update data in one or more columns determined by a list of comma-separated assignments.
Each assignment specifies a column name on the left side the assignment operator (=) and a literal value, an expression, or data from a subquery on the right side of the assignment operator.
If the item already exists, instead update the stock count of the existing item.
To do this without failing the entire transaction, use savepoints: BEGIN; -- other operations SAVEPOINT sp1; INSERT INTO wines VALUES('Chateau Lafite 2003', '24'); -- Assume the above fails because of a unique key violation, -- so now we issue these commands: ROLLBACK TO sp1; UPDATE wines SET stock = stock 24 WHERE winename = 'Chateau Lafite 2003'; -- continue with other operations, and eventually COMMIT; .
Cross table update (also known as correlated update, or multiple table update) in Oracle uses non-standard SQL syntax format (non ANSI standard) to update rows in another table. Update data in table A based on two or more common columns in table B.
The differences in syntax are quite dramatic compared to other database systems like MS SQL Server or My SQL. Updates based on two or more common columns are normally used for tables where multiple columns work together as a primary key (known as composite primary key).We are going to update column DESCRIPTION and PICTURE in table Categories_Test by using data in table Categories, based on data in the common column CATEGORY_ID. Update data in a column in table A based on a common column in table B. Update data in two columns in table A based on a common column in table B. Conditionally update data in table A based on a common column in table B. No portion may be reproduced without my written permission.The update query below shows that the PICTURE column is updated by looking up the same ID value in CATEGORY_ID column in table Categories_Test and Categories. If you need to update multiple columns simultaneously, use comma to separate each column after the SET keyword. Here we only want to update PICTURE column in Categories_Test table where the data in Category_Name column is Seafood in table Categories. Software and hardware names mentioned on this site are registered trademarks of their respective companies.The sub-query must yield no more than one row when executed.If it yields one row, its column values are assigned to the target columns; if it yields no rows, NULL values are assigned to the target columns.When using FROM, one should ensure that the join produces at most one output row for each row to be modified.