oracle/mysql java jdbc类型映射讲解

	java.sql.Types 值	Java 类型	IBM DB2	Oracle	Sybase	SQL	Informix	IBM Content Manager
	BIGINT	java.lang.long	BIGINT	NUMBER (38, 0)	BIGINT	BIGINT	INT8	DK_CM_BIGINT
	BINARY	byte[]	CHAR FOR BIT DATA	RAW	BINARY	IMAGE	BYTE	DK_CM_BLOB
	BIT	java.lang.Boolean	N/A	BIT	BIT	BIT	BIT	DK_CM_SMALLINT
	BLOB	byte[]	BLOB	BLOB	BLOB	BLOB	BLOB	DK_CM_BLOB
	CHAR	java.lang.String	CHAR, GRAPHIC	CHAR	CHAR	CHAR	CHAR	DK_CM_CHAR
	CLOB	java.lang.String	CLOB, DBCLOB	CLOB	CLOB	CLOB	CLOB	DK_CM_CLOB
	DATE	java.sql.Date	DATE	DATE	DATE	DATE	DATE	DK_CM_DATE
	DECIMAL	java.math.BigDecimal	DECIMAL	NUMBER	DECIMAL, MONEY, SMALLMONEY	DECIMAL	DECIMAL	DK_CM_DECIMAL
	DOUBLE	java.lang.Double	DOUBLE	DOUBLE PRECISION	DOUBLE PRECISION	DOUBLE PRECISION	DOUBLE PRECISION	DK_CM_DOUBLE
	FLOAT	java.lang.Double	FLOAT	FLOAT	FLOAT	FLOAT	FLOAT	DK_CM_DOUBLE
	INTEGER	java.lang.Integer	INTEGER	INTEGER	INT	INTEGER	INTEGER	DK_CM_INTEGER
	JAVA_OBJECT	java.lang.Object	JAVA_OBJECT	JAVA_OBJECT	JAVA_OBJECT	JAVA_OBJECT	OPAQUE	N/A
	LONGVARBINARY	byte[]	LONG VARCHAR FOR BIT DATA	LONG RAW	IMAGE	IMAGE	BYTE	DK_CM_BLOB
	LONGVARCHAR	java.lang.String	LONG VARCHAR, LONG VARGRAPHIC	LONG	TEXT	TEXT	TEXT	DK_CM_VARCHAR(3500)
	NUMERIC	java.math.BigDecimal	NUMERIC	NUMBER	NUMERIC	NUMERIC	NUMERIC	DK_CM_DECIMAL
	OTHER	java.lang.Object	OTHER	OTHER	OTHER	OTHER	OTHER	N/A
	REAL	java.lang.Float	REAL	REAL	REAL	REAL	REAL	DK_CM_DOUBLE
	SMALLINT	java.lang.Integer	SMALLINT	SMALLINT	SMALLINT	SMALLINT	SMALLINT	DK_CM_INTEGER
	TIME	java.sql.Time	TIME	DATE	TIME	TIME	DATETIME HOUR TO SECOND	DK_CM_TIME
	TIMESTAMP	java.sql.Timestamp	TIMESTAMP	DATE	DATETIME, SMALLDATETIME	DATETIME	DATETIME YEAR TO FRACTION (5)	DK_CM_TIMESTAMP
	TINYINT	java.lang.Bute	SMALLINT	TINYINT	TINYINT	TINYINT	TINYINT	DK_CM_INTEGER
	VARBINARY	byte[]	VARCHAR FOR BIT DATA	RAW	VARBINARY	IMAGE	BYTE	DK_CM_BLOB
	VARCHAR	java.lang.String	VARCHAR, VARGRAPHIC	VARCHAR	VARCHAR	VARCHAR	VARCHAR	DK_CM_VARCHAR

　　Oracle ResultSetMetaData getPrecision/getScale有一个bug，count(*) as xxx、abs(col) as xxx，这样xxx是无法返回正确的Scale和Precision的，要想这些情况下返回正确的值，需要使用明确的cast(xxx as datatype)。参见https://stackoverflow.com/questions/1410267/oracle-resultsetmetadata-getprecision-getscale