UPDATE-RECORDS — Updates the values of existing records.
Function
table
              A string, symbol or symbolic SQL expression representing
              the name of a table existing in
              database.
            
attributes
              A list of attribute identifiers or NIL. 
            
values
              A list of attribute values or NIL.               
            
av-pairs
              A list of attribute identifier/value pairs or NIL. 
            
whereA symbolic SQL expression.
databaseA database object. This will default to the value of *default-database*.
        Updates the attribute values of existing records satsifying
        the SQL expression where in the table
        specified by table in
        database which defaults to
        *default-database*.
      
 
        There are three ways of specifying the values to update for
        each row. In the first, values contains
        a list of values to use in the update and
        attributes and
        av-pairs are NIL. This can be used
        when values are supplied for all attributes in
        table. In the second,
        attributes is a list of column names,
        values is a corresponding list of
        values and av-pairs is NIL. In the
        third, attributes and
        values are NIL and
        av-pairs is an alist of (attribute
        value) pairs.
      
(select [first-name] [last-name] [email] 
        :from [employee]
        :where [= [emplid] 1] 
        :field-names nil)
=> (("Vladimir" "Lenin" "lenin@soviet.org"))
(update-records [employee] 
                :av-pairs'((first_name "Yuri")
                           (last_name "Gagarin")
                           (email "gagarin@soviet.org"))
                :where [= [emplid] 1])
=> 
(select [first-name] [last-name] [email] 
        :from [employee]
        :where [= [emplid] 1] 
        :field-names nil)
=> (("Yuri" "Gagarin" "gagarin@soviet.org"))
      
        An error of type sql-database-data-error is
        signalled if table is not an existing
        table in database, if the specified
        attributes are not found or if the SQL statement resulting
        from the symbolic expression where does
        not return a Boolean value.
      
If the execution of the SQL query leads to any errors, an error of type sql-database-error is signalled.