Accessing Databases with JDBC - Java: How to Program Early Objects - page 1059

Common Programming Error 24.4
It's normally an error to specify a value for an autoincrement column.

AuthorID FirstName LastName

1 Paul Deitel

2 Harvey Deitel

3 Abbey Deitel

4 Dan Quirk

5 Michael Morgano

6 Sue Red

Fig. 24.20 | Sample data from table Authors after an INSERT operation.

24.4.6 UPDATE Statement
An UPDATE statement modifies data in a table. Its basic form is

UPDATE tableName
SET columnName1 = value1 , columnName2 = value2 , …, columnNameN = valueN
WHERE criteria

where tableName is the table to update. The tableName is followed by keyword SET and a
comma-separated list of columnName = value pairs. The optional WHERE clause provides
criteria that determine which rows to update. Though not required, the WHERE clause is
typically used, unless a change is to be made to every row. The UPDATE statement

UPDATE Authors
SET LastName = 'Black'
WHERE LastName = 'Red' AND FirstName = 'Sue'

updates a row in the Authors table. The statement indicates that LastName will be assigned
the value Black for the row where LastName is Red and FirstName is Sue . [ Note: If there
are multiple matching rows, this statement will modify all such rows to have the last name
“Black.”] If we know the AuthorID in advance of the UPDATE operation (possibly because
we searched for it previously), the WHERE clause can be simplified as follows:

WHERE AuthorID = 6

Figure 24.21 shows the Authors table after the UPDATE operation has taken place.

AuthorID FirstName LastName

1 Paul Deitel

2 Harvey Deitel

3 Abbey Deitel

4 Dan Quirk

5 Michael Morgano

6 Sue Black

Fig. 24.21 | Sample data from table Authors after an UPDATE operation.