The UPDATE statement in SQL is used to modify existing records in a table by changing one or more column values.

Key Points:

• You specify the table to update.

• Use the SET clause to assign new values to columns.

• Optionally use a WHERE clause to update only specific rows.

• Without WHERE, all rows in the table are updated!

Syntax

UPDATE table_nameSET column1 = value1,    column2 = value2,    ...WHERE condition;

• WHERE condition filters which rows to update.

• Multiple columns can be updated in one statement.

Example

Update a single row

UPDATE EmployeesSET Salary = 75000WHERE EmployeeID = 101;

Update multiple columns and multiple rows

UPDATE EmployeesSET Salary = Salary * 1.1,  -- 10% raise    Title = 'Senior Developer'WHERE Department = 'IT';

Important Notes

• Always use WHERE unless you want to update every row.

• You can use expressions and subqueries in SET values.

• Some databases support RETURNING to show updated rows after execution.

If you want, I can help with examples for specific SQL databases or advanced UPDATE scenarios!