The Oracle UPDATE statement is used to update existing records in a table in an Oracle database.
There are 2 syntaxes for an update query in Oracle depending on whether you are performing a traditional update or updating one table with data from another table.
That allows us to perform operations on every record on a one-by-one basis.
The DECLARE statement declares a cursor and associates it with a SELECT statement that retrieves the rows to be traversed by the cursor.
Since you can't list more than one table in the Oracle UPDATE statement, you can use the Oracle EXISTS clause.