Updating Records

Very often data currently stored in a table needs to be corrected or changed. For example, a name may be misspelled or a salary figure increased. To modify the values of one or more columns in one or more records of a table, the user specifies the UPDATE command. The general form of this statement is:

UPDATE  table-name
     SET     column-name1 = expression1
             [,column-name2 = expression2] ...
     [WHERE  search-condition] ;