Question

我需要对此数据库进行快速递归sql查询：

SITE            CATEGORY        DIR          PARENT_CATEGORY
domain1.com     home            home         
domain1.com     kitchen         kitchen      home
domain1.com     appliances      apps         home
domain1.com     tables          tables       kitchen

domain2.com     home            home-dir     
domain2.com     bathroom        bath         
domain2.com     garden          garden       

domain3.com     fun             funny

我需要的是一个函数，它将为我提供从当前到顶级类别的父类别数组。例如，对于domain1.com表，它应该返回：

$breadcrumb = Array(
[0]=>Array(
   'title'='home',
   'dir'='home'
);
[1]=>Array(
   'title'='kitchen',
   'dir'='kitchen'
);
[2]=>Array(
   'title'='tables',
   'dir'='tables'
);

);

所以基本上，它应该返回所请求类别＆amp;的痕迹现场。功能（$ category，$ site）{...

返回数组。 }

Answer 1

查询有效，将为您提供最多7级的层次结构深度以及单行中的所有父级。有点像：

SITE            CATEGORY        level1       level2     level3   level4   level5 
--------------------------------------------------------------------------------
domain1.com     tables          tables       kitchen    home     NULL     NULL

select level1, level2, site, category, dir, parent_category
        if(level7 is not null,7,
            if(level6 is not null and level7 is null,6,
                if(level5 is not null and level6 is null,5,
                    if(level4 is not null and level5 is null,4,
                        if(level3 is not null and level4 is null,3,
                            if(level2 is not null and level3 is null,2,1)))))) depth 
  from
      (select  
          site,category,dir,parent_category
          site level1, 
          parent_category level2, 
          (select parent_category from <table> i where one.parent_category=i.category) level3, 
          (select parent_category from <table> i where level3=i.category) level4, 
          (select parent_category from <table> i where level4=i.category) level5, 
          (select parent_category from <table> i where level5=i.category) level6, 
          (select parent_category from <table> i where level6=i.category) level7  
      from  
          <table> one
          WHERE one.site = ?              
      )a;

注意：你可能需要做一些调整

面包屑的递归sql查询

1 个答案: