Oracle in a Nutshell

Data Mapping

The datatypes used by an Oracle database are not exactly the same as the datatypes in Java. Table 11-1 summarizes the mapping from Java database datatypes to Oracle datatypes.

Some of the java.lang datatypes are wrapper classes for the Java primitive datatypes that can accept a NULL reference, because normal Java datatypes cannot. To retrieve a value from a wrapper class, use the appropriate method typeValue( ) for each wrapper class.

Table 11-1. Datatype mapping between Java and Oracle

Java datatype	Oracle datatype
java.sql.Array	ARRAY
java.sqlBlob	BLOB
Boolean java.lang.Boolean	NUMBER
byte java.lang.byte	NUMBER
byte[]	RAW LONGRAW
java.slq.Clob	CLOB
java.sql.date	DATE
double java.lang.double	NUMBER
float java.lang.float	NUMBER
int java.lang.Integer	NUMBER
long java.lang.Long	NUMBER
java.sql.Ref	REF
short java.lang.Short	NUMBER
java.lang.string	VARCHAR2 LONG RAW
java.sql.Struct	STRUCT
java.sql.time	DATE
java.sql.timestamp	DATE
java.math.BigDecimal(recommended)	NUMBER

There are also sets of Oracle extensions for the following Oracle datatypes. The oracle.sql.NUMBER extension allows you to store and retrieve Oracle NUMBER data without losing any precision.

oracle.sql.ARRAY	oracle.sql.NUMBER
oracle.sql.BFILE	oracle.sql.RAW
oracle.sql.BLOB	oracle.sql.REF
oracle.sql.CHAR	oracle.sql.ROWID
oracle.sql.CLOB	oracle.sql.STRUCT
oracle.sql.DATE