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HomeDatabaseMysql Tutorialhibernate数据类型,标准sql数据类型之间的对应表_MySQL

Hibernate

记录下hibernate mysql映射类型对应表:


1.常规Hibernate 映射
映射类型  JAVA类型  标准SQL类型  描述
 integer或int  int 或者 java.lang.Integer  INTEGER  4 字节
 long  long Long  BIGINT  8 字节
 short  short Short  SMALLINT

2 字节

 byte  byte Byte  TINYINT

1 字节

 float  float Float  FLOAT  4 字节
 double  double Double  DOUBLE  字节
 big_decimal  java.math.BigDecimal  NUMERIC  NUMERIC(8,2)8 位
 character  char Character String  CHAR(1)  定长字符
 string  String  VARCHAR  变长字符串
 boolean  boolean Boolean  BIT  布尔类型
 yes_no  boolean Boolean  CHAR(1) (Y-N)  布尔类型
 true_false  boolean Boolean  CHAR(1) (T-F)  布尔类型


2 、 Java 时间和日期类型的 Hibernate 映射

映射类型

Java 类型

标准 SQL 类型

描述

date

util.Date 或者 sql.Date

DATE

YYYY-MM-DD

time

Date Time

TIME

HH:MM:SS

timestamp

Date Timestamp

TIMESTAMP

YYYYMMDDHHMMSS

calendar

calendar

TIMESTAMP

YYYYMMDDHHMMSS

calendar_date

calendar

DATE

YYYY-MM-DD


3 、 Java 大对象类型的 Hibernate 映射类型

映射类型

Java 类型

标准 SQL 类型

MySQL 类型

Oracle 类型

binary

byte[]

VARBINARY( 或 BLOB)

BLOB

BLOB

text

String

CLOB

TEXT

CLOB

serializable

Serializable 接口任意实现类

VARBINARY( 或 BLOB)

BLOB

BLOB

clob

java.sql.Clob

CLOB

TEXT

CLOB

blob

java.sql.Blob

BLOB

BLOB

BLOB

   

在程序中通过 Hibernate 来保存 java.sql.Clob 或者 java.sql.Blob 实例时,必须包含两个步骤:

1.在一个数据库事务中先保存一个空的 Blob 或 Clob 实例。

2.接着锁定这条记录,更新上面保存的 Blob 或 Clob 实例,把二进制数据或文本数据写到 Blob 或 Clob 实例中

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