UPDATE table_name
SET variable = 'changed field', variable = 'another changed field'
WHERE firstline_name = 1;

DELETE FROM table_name WHERE condition;
In this statement: First, specify the table from which you delete data.
Second, use a condition to specify which rows to delete in the WHERE clause.
for example:
DELETE FROM customers WHERE id = 1;

UPDATE [LOW_PRIORITY] [IGNORE] table_name
SET column_name1 = expr1, column_name2 = expr2, ...
[WHERE condition];

-- Things in brackets are optional
-- IGNORE modifier updates rows even if errors occur (ie: the rows that cause errors are simply not updated)
UPDATE [IGNORE] table_name
SET column_name1 = expr1, column_name2 = expr2, ...
[WHERE condition]; -- WHERE tells us which rows to update based on said condition

UPDATE Customers SET City='Oslo'

UPDATE table_name SET column1=value1, column2=value2 WHERE condition

UPDATE Table_name
-- The desired value
SET Column_name = desired_value
-- Any value, of the item, of which one value you want to change
WHERE Column_name = value

UPDATE table_name SET field1 = new-value1, field2 = new-value2
[WHERE Clause]