UPDATE:

Updating a table based on joining another table: You can update data in a table based on data from another table using a JOIN condition:

UPDATE person
SET state_code = cities.state_code
FROM cities
WHERE cities.city = person.city;

In this example, the person table is updated based on a join with the cities table, matching the city columns.

Update all rows in a table: To update all rows in a table, you can use a simple syntax:

UPDATE person SET planet = 'Earth';

This will set the value of the planet column to 'Earth' for all rows in the person table.

Update all rows meeting a condition: If you want to update rows that meet a specific condition, you can use the WHERE clause:

UPDATE person SET state = 'NY' WHERE city = 'New York';

This will set the value of the state column to 'NY' for all rows where the city column is 'New York'.

Updating multiple columns in a table: You can update multiple columns in a table in the same statement:

UPDATE person
SET country = 'USA',
    state = 'NY'
WHERE city = 'New York';

This will update the country and state columns for rows where the city column is 'New York'.