The UPDATE statement is used to make changes to data in a table. You can alter the values in one or more columns of a single row or several rows. After the UPDATE keyword, enter the name of the table for which you want to update data. Second, in the SET clause, define which column you wish to update and the new value. You utilize a list of comma-separated assignments to update values in several columns by providing a value in each column’s assignment in the form of a literal value, an expression, or a subquery. Third, use a condition in the WHERE clause to determine which rows should be updated. The “where” clause is not required. If you leave it out, the UPDATE statement will change all of the rows in the table.  You should keep in mind that the WHERE clause is quite critical. You may want to update only one row at a time; however, you may forget to utilize the WHERE clause and update all rows of the table.