Hibernate单表操作

1，单一主键

.assigned 由java应用程序负责生成（手工赋值）。

.native  有底层数据库自动生成标示符 ，MySQL auto_increment

2，基本类型

java类型跟数据库类型的映射关系

映射类型                                java类型                                                         标准sql类型

date                                 java.util.Date or java.sql.Date                                DATE

time                                java.util.Date or java.sql.Time                               TIME

timestamp                      java.util.Date or  java.sql.Times                           TIMESTAMP

calender                          java.util.Calendar                                                  TIMESTAMP

calender_date               java.util.Calendar                                                    DATE

3，对象类型

映射类型                          java类型                                                                      标准SQL类型                                                MYSQL类型   

binary                                byte[]                                                                     VARCHAR or BLOB                                                  BLOB

text                                     java.lang.String                                                             CLOB                                                                TEXT

clob                                     java.sql.Clob                                                            CLOB                                                                    TEXT

blob                                       java.sql.Blob                                                               BLOB                                                                BLOB

在mysql当中不支持sql的CLOB类型 在mysql当中用TEXT.

BLOB常常是数据库中用来存储二进制文件的字段类型