Valid SQL-JDBC Datatype Mappings

Table 3-2 in Chapter 3 describes the default mappings between Java classes and SQL datatypes supported by the Oracle JDBC drivers. Compare the contents of the JDBC Datatypes, Standard Java Types and SQL Datatypes columns in Table 3-2 with the contents of Table 18-1 below.

Table 18-1 lists all the possible Java types to which a given SQL datatype can be validly mapped. The Oracle JDBC drivers will support these "non-default" mappings. For example, to materialize SQL CHAR data in an oracle.sql.CHAR object use the getCHAR() method. To materialize it as a java.math.BigDecimal object, use the getBigDecimal() method.

Table 18-1 Valid SQL Datatype-Java Class Mappings

These SQL datatypes:	Can be materialized as these Java types:
CHAR, VARCHAR2, LONG	oracle.sql.CHAR
	java.lang.String
	java.sql.Date
	java.sql.Time
	java.sql.Timestamp
	java.lang.Byte
	java.lang.Short
	java.lang.Integer
	java.lang.Long
	java.lang.Float
	java.lang.Double
	java.math.BigDecimal
	byte, short, int, long, float, double
DATE	oracle.sql.DATE
	java.sql.Date
	java.sql.Time
	java.sql.Timestamp
	java.lang.String
NUMBER	oracle.sql.NUMBER
	java.lang.Byte
	java.lang.Short
	java.lang.Integer
	java.lang.Long
	java.lang.Float
	java.lang.Double
	java.math.BigDecimal
	byte, short, int, long, float, double
RAW, LONG RAW	oracle.sql.RAW
	byte[]
ROWID	oracle.sql.CHAR
	oracle.sql.ROWID
	java.lang.String
BFILE	oracle.sql.BFILE
BLOB	oracle.sql.BLOB
	java.sql.Blob (oracle.jdbc2.Blob under JDK 1.1.x)
CLOB	oracle.sql.CLOB
	java.sql.Clob (oracle.jdbc2.Clob under JDK 1.1.x)
OBJECT	oracle.sql.STRUCT
	java.sql.Struct (oracle.jdbc2.Struct under JDK 1.1.x)
	oracle.sql.CustomDatum
	oracle.sql.SqlData
REF	oracle.sql.REF
	java.sql.Ref (oracle.jdbc2.Ref under JDK 1.1.x)
TABLE (nested), VARRAY	oracle.sql.ARRAY
	java.sql.Array (oracle.jdbc2.Array under JDK 1.1.x)
any of the above SQL types	oracle.sql.CustomDatum or oracle.sql.Datum

Notes: The type UROWID is not supported. The oracle.sql.Datum class is abstract. The value passed to a parameter of type oracle.sql.Datum must be of the Java type corresponding to the underlying SQL type. Likewise, the value returned by a method with return type oracle.sql.Datum must be of the Java type corresponding to the underlying SQL type. The mappings to oracle.sql classes are optimal if no conversion from SQL format to Java format is necessary.

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