Hibernate Tutorial-mapping types

There are two types of hibernate mappings: The built-in mapping type and the custom mapping type. The built-in mapping type is responsible for mapping some common Java types to the appropriate SQL type, and hibernate also allows users to implement Usertype or Compositeusertype interfaces to flexibly customize custom mapping types. A custom type can map a user-defined Java type to a corresponding field in a database table.

First, Hibernate's built-in mapping type

1. Types of hibernate mappings for Java basic types

Hibernate Mapping type	Java Type	Standard SQL type	Size and range of values
integer or int	int or java.lang.Integer	INTEGER	4 bytes
Long	Long Long	BIGINT	8 bytes
Short	Short Short	SMALLINT	2 bytes
Byte	BYTE byte	TINYINT	1 bytes
Float	float float	FLOAT	4 bytes
Double	Double Double	DOUBLE	8 bytes
Big_decimal	Java.math.BigDecimal	NUMERIC	NUMERIC (8,2) 8 -bit
Character	Char Character String	CHAR (1)	Fixed-length characters
String	String	VARCHAR	Variable length string
Boolean	Boolean Boolean	BIT	Boolean type
Yes_no	Boolean Boolean	CHAR (1) (y-n)	Boolean type
True_false	Boolean Boolean	CHAR (1) (T-F)	Boolean type

2. Hibernate mappings for Java time and date types

Mapping type	Java Type	Standard SQL type	Describe
Date	util. Date or 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. Types of hibernate mappings for Java large object types

style= "font-family: ' Times New Roman ';" >serializable interface arbitrary implementation class

TD valign= "Top" width= "

Map type	style= font-family Times New Roman '; " >java type	Standard sql type	mysql type	oracle type
binary	style= "font-family: ' Times New Roman ';" >byte[]	varbinary ( or blob)	blob	blob
text	style= "font-family: ' Times New Roman ';" >string	clob	text	clob
serializable	varbinary ( or blob)	blob	blob
clob	style= "font-family: ' Times New Roman ';" >java.sql.clob	style= "font-family: ' Times New Roman ';" >clob	text	clob
Blob	Java.sql.Blob	Blob	Blob	Blob

When you save a Java.sql.Clob or Java.sql.Blob instance through hibernate in your program, you must include two steps:

L Save an empty blob or CLOB instance in a database transaction first.

L then lock the record, update the saved blob or CLOB instance, and write the binary data or text data to the BLOB or CLOB instance.

4. Hibernate mapping type of individual Java classes with JDK (slightly)

5. Use hibernate built-in mapping type

Ii. Customized mapping type (slightly)

End!

Hibernate Tutorial-mapping types