2009-02-28

DATE, TIME, and TIMESTAMP of SQL Standard

The followings are definition of DATE, TIME, and TIMESTAMP data type of SQL standard.

These are somewhat confusing to Java developers, because Date class of JDK represents a specific instant in time, with millisecond precision and there's no basic classes(except java.sql.Date, java.sql.Time which are restricted to JDBC) that represent pure date and pure time separately.

-  DATE - contains the <datetime field>s YEAR, MONTH, and DAY;

-  TIME - contains the <datetime field>s HOUR, MINUTE, and SECOND;

-  TIMESTAMP - contains the <datetime field>s YEAR, MONTH, DAY, HOUR, MINUTE, 
               and SECOND.

The above definition is from SQL-92 standard draft which you can get from here.

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