SQL Update Command

How do you modify existing data in a SQL table?

The SQL UPDATE command is used to modify existing data in a table. It allows you to change values in specific rows based on conditions. This is a fundamental operation for maintaining and updating database information.

Description

SELECT CURDATE();
SELECT CURRENT_DATE;
SELECT NOW();
SELECT CURRENT_TIMESTAMP;
SELECT GETDATE(); -- For SQL Server
SELECT SYSDATE(); -- For Oracle

Common Mistakes

• Forgetting the `WHERE` clause: Updating all rows without a `WHERE` clause can lead to unintended data changes.
• Using incorrect data types in the `SET` clause: Ensure the values you're updating match the data types of the columns.
• Typos in column names or table names: Carefully check for typos to avoid errors.
• Incorrect use of comparison operators in the `WHERE` clause: Using the wrong operator can result in incorrect data updates.