mybatis 数据库类型JDBC type和Java类型之间的关系：

JDBC Type                            Java Type 
CHAR                                     String 
VARCHAR                              String 
LONGVARCHAR                    String 
NUMERIC                        java.math.BigDecimal 
DECIMAL                         java.math.BigDecimal 
BIT                                        boolean
BOOLEAN                            boolean 
TINYINT                                  byte 
SMALLINT                              short 
INTEGER                                int 
BIGINT                                    long 
REAL                                      float 
FLOAT                                   double 
DOUBLE                               double 
BINARY                                 byte[] 
VARBINARY                          byte[] 
LONGVARBINARY                byte[] 
DATE                                  java.sql.Date 
TIME                                   java.sql.Time 
TIMESTAMP                       java.sql.Timestamp 
CLOB                                     Clob 
BLOB                                     Blob 
ARRAY                                  Array 
DISTINCT                           mapping of underlying type 
STRUCT                                Struct 
REF                                        Ref