Mysql树形结构数据Closure Table做树

1 新增菜单表

CREATE TABLE `menu` (
  `id` int(11) DEFAULT NULL,
  `name` varchar(100) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8

INSERT INTO `menu` VALUES ('1', '1');
INSERT INTO `menu` VALUES ('2', '2');
INSERT INTO `menu` VALUES ('3', '1.1');
INSERT INTO `menu` VALUES ('4', '2.1');
INSERT INTO `menu` VALUES ('5', '1.1.1');
INSERT INTO `menu` VALUES ('6', '1.1.2');
INSERT INTO `menu` VALUES ('7', '2.1.1');
INSERT INTO `menu` VALUES ('8', '2.1.2');

2 新增菜单组织表

parent_id 父节点

root_id 根节点

depth 距离根节点长度

is_leaf 是否叶子节点

node_id 节点

CREATE TABLE `menu_relation` (
  `parent_id` int(11) DEFAULT NULL,
  `root_id` int(11) DEFAULT NULL,
  `depth` int(11) DEFAULT NULL,
  `is_leaf` tinyint(1) DEFAULT NULL,
  `node_id` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

 

insert into menu_relation values(null,1,0,0,1);
insert into menu_relation values(1,1,1,0,3);
insert into menu_relation values(3,1,2,1,5);
insert into menu_relation values(3,1,2,1,6);

insert into menu_relation values(null,2,0,0,1);
insert into menu_relation values(2,2,1,0,4);
insert into menu_relation values(4,2,2,1,7);
insert into menu_relation values(4,2,2,1,8);

insert into menu_relation values(1,3,0,0,3);
insert into menu_relation values(3,3,1,1,5);
insert into menu_relation values(3,3,1,1,6);

insert into menu_relation values(2,4,0,0,4);
insert into menu_relation values(4,4,1,1,7);
insert into menu_relation values(4,4,1,1,8);

insert into menu_relation values(3,5,0,1,5);
insert into menu_relation values(3,6,0,1,6);
insert into menu_relation values(4,7,0,1,7);
insert into menu_relation values(4,8,0,1,8);

3 获取菜单的组织结构

1 首先获取所有菜单

select * from menu_relation;

2 List转成树形结构

public List<TreeNode> ListToTree(List<TreeNode> all){
        List<TreeNode> result = new ArrayList<TreeNode>();
        
        all.forEach(node->{
            boolean flag = false;
            
            for(TreeNode node2:all){
                
                if(node.getParentId()!=null && node.getParentId().equals(node2.getId())){
                    flag = true;
                    if(node2.getChild()==null){
                        node2.setChild(new ArrayList<TreeNode>());
                    }
                    node2.getChild().add(node);
                    break;
                }
            }
            
            if(!flag){
                result.add(node);
            }
        });
        
        return result;
    }

public class TreeNode {
    
    
    private String name;
    
    private String id;
    
    private String parentId;
    
    private List<TreeNode> child;

    public String getName() {
        return name;
    }

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

    public String getId() {
        return id;
    }

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

    public String getParentId() {
        return parentId;
    }

    public void setParentId(String parentId) {
        this.parentId = parentId;
    }

    public List<TreeNode> getChild() {
        return child;
    }

    public void setChild(List<TreeNode> child) {
        this.child = child;
    }    
}

4 获取某个节点下的所有菜单

select * from menu_relation where root_id = '';