mysql怎么在单位表和部门表中实现树形结构查询

[pingzi_com]

t_company
id name
1 单位1
2 单位2
3 单位3
4 单位4

t_department
id company_id name
1 1 部门1
2 1 部门2
3 2 部门3
4 2 部门1
实现结果如下：
单位1
部门1
部门2
单位2
部门3
部门1
求解！！！

[pingzi_com]

要怎么设计，用什么控件，可以给我说下吧

[pingzi_com]

用代码存是不是太慢了，如果我要在节点上添加怎么办

[五哥]

dhtmlXTree

自己去找例子

[五哥]

select c.id, c.name as cName , d.name as dName from t_company c left join t_department d on c.id = d.company_id order by c.id

只能是查出来 ，然后在构建一棵树了

[pingzi_com]

要怎么建树呢？能详细给我说下吗？

[五哥]

import java.util.ArrayList;
import java.util.List;


public class CompanyList {

	private List companys = new ArrayList() ;
	public List getCompanys() {
		return companys;
	}

	public void add(Company com){
		companys.add(com) ;
	}
	
	public Company getCompany(int id){
		
		for (int i = 0; i < companys.size(); i++){
			if (((Company)companys.get(i)).getId() == id){
				return  (Company)companys.get(i) ;
			}
		}
		return null ;
	}
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		CompanyList comList = new CompanyList() ;
		
		//自己查数据库得到数据,此处手工创建数据 
		comList.add(new Company(1, "单位1")) ;
		comList.add(new Company(2, "单位2")) ;
		comList.add(new Company(3, "单位3")) ;
		comList.add(new Company(4, "单位4")) ;
		
		Company com = null ;
		Department dept = new Department(1, 1, "部门1") ;
		com = comList.getCompany(dept.getCompanyId()) ;
		if (com != null ){
			com.add(dept) ;
		}
		
		dept = new Department(1, 1, "部门2") ;
		com = comList.getCompany(dept.getCompanyId()) ;
		if (com != null ){
			com.add(dept) ;
		}
		dept = new Department(1, 2, "部门3") ;
		com = comList.getCompany(dept.getCompanyId()) ;
		if (com != null ){
			com.add(dept) ;
		}
		dept = new Department(1, 3, "部门1") ;
		com = comList.getCompany(dept.getCompanyId()) ;
		if (com != null ){
			com.add(dept) ;
		}
			
		List list = comList.getCompanys() ;
		for (int i = 0 ;i < list.size(); i++){
			com = (Company)list.get(i) ;
			System.out.println(com.getName()) ;
			com.printDept() ;
		}
		
		System.out.println("***打印结束***");


	}

}

import java.util.ArrayList;
import java.util.List;

public class Company {

   private int id ;
   private String name ;
   
   
   public int getId() {
	return id;
}

public void setId(int id) {
	this.id = id;
}

public String getName() {
	return name;
}

public void setName(String name) {
	this.name = name;
}

public List getDepartments() {
	return departments;
}

public void setDepartments(List departments) {
	this.departments = departments;
}


//getter and setter ;
   private List departments = new ArrayList() ;
   
   public void add(Department dept){
     	departments.add(dept) ;
   }
   
   public Company() {
   }   
   public Company(int id, String name) {
	this.id = id;
	this.name = name;
}

public void printDept() {

	List list = this.getDepartments() ;
	Department dept = null ;
	for (int i = 0; i <list.size(); i++){
		
		dept = (Department ) list.get(i) ;
		System.out.println("  --" + dept.getName()) ;
	}
	
}


}

public class Department {

	private int id;
	private int companyId ;
	public int getCompanyId() {
		return companyId;
	}

	public void setCompanyId(int companyId) {
		this.companyId = companyId;
	}

	private String name;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Department() {

	}

	public Department(int id, int companyId, String name) {
		super();
		this.id = id;
		this.companyId = companyId ;
		this.name = name;
	}

}

结果：

单位1
--部门1
--部门2
单位2
--部门3
单位3
--部门1
单位4
***打印结束***

[ylovep]

关键是数据库设计
id name code 根节点 父节点
至于显示可以 用控件

[xueshan666]

懒惰大于一切，不解释

[爱在程序]

最简单的做法两个表之间建一个主外键进行关联；这样维护起来比较方便；

[NullPointException]

http://download.csdn.net/download/w8320273/4361038
正好前段时间写了个小例子，使用ztree插件，需要可以试试