摘要:
转自尚学堂教学视频 package com.bjsxt.hibernate; import java.util.HashSet; import java.util.Set; import javax.persistence.CascadeType; import javax.persistence.Entity; import javax.persistence.Fetc... 阅读全文
摘要:
package com.bjsxt.hibernate; import java.util.HashSet; import java.util.Set; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import j... 阅读全文
摘要:
多对多会利用中间表做外键的形式关联 package com.bjsxt.hibernate; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.ManyToOne; ... 阅读全文
摘要:
package com.bjsxt.hibernate; import java.util.HashSet; import java.util.Set; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import j... 阅读全文
摘要:
package com.bjsxt.hibernate;import java.util.HashSet; import java.util.Set;import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.OneToMany; import javax.persistence.Table;@Ent... 阅读全文
摘要:
(转自尚学堂教学内容) 注解多对一: package com.bjsxt.hibernate; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; @E... 阅读全文
摘要:
注解方式: import javax.persistence.Embedded; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; i... 阅读全文
摘要:
package com.bjsxt.hibernate; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.pe... 阅读全文
摘要:
单向双向在数据库中没有区别,但是在java程序中有区别。 在程序中:双向的通过一个就可以找到另一个,单向的通过设置了对应关系的类可以找到它所对应的类,反过来就不行。 注解方式单向主键关联: 和外键一样,只不过注解由@JoinColumn变成@PrimaryKeyJoinColumn import javax.persistence.Entity; import jav... 阅读全文