Mapping Database Types to Java

The package java.sql contains a number of data types for compatibility with SQL database types. Some of these types are shown in Table.

Java format types

Although, not directly related to JDBC, the package java.text contains a number of classes which can be used for formatting output. The classes provided here include those to format java.util.Date and floating point numbers for display output.

Here is an example of using the class DateFormat to format a date for display purposes:

Calendar cal = Calendar.getInstance (TimeZone.getTimeZone (“AET”),

                                                                           new Locale (“AU”, “EN”));

Date aDate = cal.getTime ();

DateFormat df = DateFormat.getDateTimeInstance ();

df.setTimeZone (TimeZone.getTimeZone (“AET”));

String date = df.format (aDate);

System.out.println (“Date is:” + date);

Note that in the versions of Java prior to Java 2, simply obtaining a java.util.Date object does not work, as there is a problem with localities outside the United States. Therefore, some of these methods have been deprecated, and the method Calendar is to be used instead.

                                             Table Java and SQL data types.