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  • MySQL递归查询所有子节点,树形结构查询

    --表结构

    CREATE TABLE `address` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `code_value` varchar(32) DEFAULT NULL COMMENT '区域编码',
    `name` varchar(128) DEFAULT NULL COMMENT '区域名称',
    `remark` varchar(128) DEFAULT NULL COMMENT '说明',
    `pid` varchar(32) DEFAULT NULL COMMENT 'pid是code_value',
    PRIMARY KEY (`id`),
    KEY `ix_name` (`name`,`code_value`,`pid`)
    ) ENGINE=InnoDB AUTO_INCREMENT=1033 DEFAULT CHARSET=utf8 COMMENT='行政区域表';

     


    --mysql 实现树结构查询
    --方法一

    CREATE PROCEDURE sp_showChildLst(IN rootId varchar(20))
    BEGIN
    CREATE TEMPORARY TABLE IF NOT EXISTS tmpLst
    (sno int primary key auto_increment,code_value VARCHAR(20),depth int);
    DELETE FROM tmpLst;

    CALL sp_createChildLst(rootId,0);

    select tmpLst.*,address.* from tmpLst,address where tmpLst.code_value=address.code_value order by tmpLst.sno;
    END

     

    CREATE PROCEDURE sp_createChildLst(IN rootId varchar(20),IN nDepth INT)
    BEGIN
    DECLARE done INT DEFAULT 0;
    DECLARE b VARCHAR(20);
    DECLARE cur1 CURSOR FOR SELECT code_value FROM address where pid=rootId;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

    insert into tmpLst values (null,rootId,nDepth);

    SET @@max_sp_recursion_depth = 10;
    OPEN cur1;

    FETCH cur1 INTO b;
    WHILE done=0 DO
    CALL sp_createChildLst(b,nDepth+1);
    FETCH cur1 INTO b;
    END WHILE;

    CLOSE cur1;
    END

    --方法二(此方法有线程安全问题)

    CREATE PROCEDURE sp_getAddressChild_list(in idd varchar(36))
    begin
    declare lev int;
    set lev=1;
    drop table if exists tmp1;
    CREATE TABLE tmp1(code_value VARCHAR(36),`name` varchar(50),pid varchar(36) ,levv INT);
    INSERT tmp1 SELECT code_value,`name`,pid,1 FROM address WHERE pid=idd;
    while row_count()>0
    do
    set lev=lev+1;
    INSERT tmp1 SELECT t.code_value,t.`name`,t.pid,lev from address t join tmp1 a on t.pid=a.code_value AND levv=lev-1;
    end while ;
    INSERT tmp1 SELECT code_value,`name`,pid,0 FROM address WHERE code_value=idd;
    SELECT * FROM tmp1;
    end

    --方法三

    CREATE FUNCTION fn_getAddress_ChildList_test(rootId INT) RETURNS varchar(1000) CHARSET utf8 #rootId为你要查询的节点
    BEGIN

    #声明两个临时变量
    DECLARE temp VARCHAR(1000);
    DECLARE tempChd VARCHAR(1000);
    SET temp = '$';
    SET tempChd=CAST(rootId AS CHAR);#把rootId强制转换为字符

    WHILE tempChd is not null DO
    SET temp = CONCAT(temp,',',tempChd);#循环把所有节点连接成字符串。
    SELECT GROUP_CONCAT(code_value) INTO tempChd FROM address where FIND_IN_SET(pid,tempChd)>0;
    END WHILE;
    RETURN temp;

    END

    --方法四

    CREATE PROCEDURE sp_findAddressChild(iid varchar(50),layer bigint(20))
    BEGIN
    /*创建接受查询的临时表 */
    create temporary table if not exists tmp_table(id varchar(50),code_value varchar(50),name varchar(50),pid VARCHAR(50)) ENGINE=InnoDB DEFAULT CHARSET=utf8;
    /*最高允许递归数*/
    SET @@max_sp_recursion_depth = 10 ;
    call sp_iterativeAddress(iid,layer);/*核心数据收集*/
    select * from tmp_table ;/* 展现 */
    drop temporary table if exists tmp_table ;/*删除临时表*/
    END


    CREATE PROCEDURE sp_iterativeAddress(iid varchar(50),layer bigint(20))
    BEGIN
    DECLARE t_id INT;
    declare t_codeValue varchar(50) default iid ;
    declare t_name varchar(50) character set utf8;
    declare t_pid varchar(50) character set utf8;

    /* 游标定义 */
    declare cur1 CURSOR FOR select id,code_value,`name`,pid from address where pid=iid ;
    declare CONTINUE HANDLER FOR SQLSTATE '02000' SET t_codeValue = null;

    /* 允许递归深度 */
    if layer>0 then
    OPEN cur1 ;
    FETCH cur1 INTO t_id,t_codeValue,t_name,t_pid ;
    WHILE ( t_codeValue is not null )
    DO
    /* 核心数据收集 */
    insert into tmp_table values(t_id,t_codeValue,t_name,t_pid);
    call sp_iterativeAddress(t_codeValue,layer-1);
    FETCH cur1 INTO t_id,t_codeValue,t_name,t_pid ;
    END WHILE;
    end if;
    END

    --方法五 SQL实现

    SELECT `name`,code_value AS code_value,pid AS 父ID ,levels AS 父到子之间级数, paths AS 父到子路径 FROM (
    SELECT `name`,code_value,pid,
    @le:= IF (pid = 0 ,0,
    IF( LOCATE( CONCAT('|',pid,':'),@pathlevel) > 0 ,
    SUBSTRING_INDEX( SUBSTRING_INDEX(@pathlevel,CONCAT('|',pid,':'),-1),'|',1) +1
    ,@le+1) ) levels
    , @pathlevel:= CONCAT(@pathlevel,'|',code_value,':', @le ,'|') pathlevel
    , @pathnodes:= IF( pid =0,',0',
    CONCAT_WS(',',
    IF( LOCATE( CONCAT('|',pid,':'),@pathall) > 0 ,
    SUBSTRING_INDEX( SUBSTRING_INDEX(@pathall,CONCAT('|',pid,':'),-1),'|',1)
    ,@pathnodes ) ,pid ) )paths
    ,@pathall:=CONCAT(@pathall,'|',code_value,':', @pathnodes ,'|') pathall
    FROM address,
    (SELECT @le:=0,@pathlevel:='', @pathall:='',@pathnodes:='') vv
    ORDER BY pid,code_value
    ) src
    ORDER BY pid

    --方法6  存储过程(SQL实现)

    create procedure query_all_add_children(in inPid varchar(50))
    begin
    select id,code_value,name,remark,pid,p2id,p3id,p4id,p5id
    from(
    select a1.id,a1.code_value,a1.name,a1.remark,
    a1.pid,a2.pid p2id,a3.pid p3id,a4.pid p4id,a5.pid p5id
    from
    address a1 left join address a2
    on(a1.pid=a2.code_value)
    left join address a3
    on(a2.pid=a3.code_value)
    left join address a4
    on(a3.pid=a4.code_value)
    left join address a5
    on(a4.pid=a5.code_value)
    ) al
    where
    (pid=inPid
    or p2id=inPid
    or p3id=inPid
    or p4id=inPid
    or p5id=inPid
    );
    end

     

    个人的一些理解:我是用的方法一:取出所有节点利用MySql函数截取所需要的字符串,然后在SQL中字段IN(调用此方法)来进行查询,这样效率比较高,方法6效率也较高,其他方法都有效率问题。 

     

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  • 原文地址:https://www.cnblogs.com/zf29506564/p/5588153.html
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