If you incorrectly specify your search condition you might update too many rows, or not enough rows.Additionally if you forget the WHERE clause altogether, you will update the entire table when you might not intend to.
These two different tables will be used in my UDPATE statement examples below.
There may be times when you need to write some code to update a row, or set of rows in a table.
Below is the basic syntax for the UPDATE statement: This is not the complete syntax of the update statement.
If you want to review the complete syntax of the UPDATE statement then please refer to Books Online.
Suppose I wanted to change all the prices of my Toys with a single UPDATE statement.
I can do that with the following code: In this code I updated the Toy table based on values in another table, in this case a table named New Toy Price.
What is the SQL update syntax to update more than one column?
Answer: The landmark book "Advanced Oracle SQL Tuning The Definitive Reference" is filled with valuable information on Oracle SQL Tuning.
I can update multiple columns with a single UPDATE statement.
Below is an example that does this: I updated the Toy Name and the Price for the Toy row with an ID value of 4, which was my original Super Surfer row.
Here is an example where I specified the WHERE clause incorrectly and I updated too many rows: Here I updated Toy Name on two rows, the “Silver Magic” and the “Super Surfer” Toyname rows.