Question

有没有一种方法可以在Oracle中为父子关系数据创建JSON对象？例如组织结构。表格包含

EmpId   Name    Title   ManagerId
1       John    GM          0
2       Smith   Manager     1
3       Jason   Manager     1
4       Will    IP1         3
5       Jade    AM          3
6       Mark    IP2         5
7       Jane    AM2         5
8       Tamara  M1          1
9       Dory    M2          1

可能会出现类似JSON对象以下的内容。

 {
      'name': 'John',
      'title': 'GM',
      'children': [
        { 'name': 'Smith', 'title': 'manager' },
        { 'name': 'Jason', 'title': 'manager',
          'children': [
            { 'name': 'Will', 'title': 'IP1' },
            { 'name': 'Jade', 'title': 'AM',
              'children': [
                { 'name': 'Mark', 'title': 'IP2' },
                { 'name': 'Jane', 'title': 'AM2' }
              ]
            }
          ]
        },            
        { 'name': 'Tamara', 'title': 'M1' },
        { 'name': 'Dory', 'title': 'M2' }
      ]
    }

Answer 1

Oracle数据库12.2确实具有许多JSON生成功能。但是这些用途有限。您需要递归构建文档。

我认为这需要一些手工制作。

首先使用递归查询创建组织结构图，并添加每个人在层次结构中的级别。

然后通过以下方式构建JSON：

如果下一行的级别大于当前级别，则该员工为经理。并且您需要启动一个子数组。否则返回当前行的JSON对象
如果当前行是树中的最后一行，则需要关闭N个数组和对象。 N是树中该行的深度减去一。
否则，如果下一行比当前级别低，则需要关闭（当前级别-下一级别）数组和对象
然后，如果下一个级别等于或小于当前级别，请添加逗号

哪个给出类似的内容：

create table t (
  EmpId   int,
  Name    varchar2(10),
  Title   varchar2(10),
  ManagerId int
);

insert into t values (1, 'John', 'GM' , 0 );
insert into t values (2, 'Smith', 'Manager' , 1 );
insert into t values (3, 'Jason', 'Manager' , 1 );
insert into t values (4, 'Will', 'IP1' , 3 );
insert into t values (5, 'Jade', 'AM' , 3 );
insert into t values (6, 'Mark', 'IP2' , 5 );
insert into t values (7, 'Jane', 'AM2' , 5 );
insert into t values (8, 'Tamar', 'M1' , 1 );
insert into t values (9, 'Dory', 'M2' , 1 );
commit;

with chart ( 
  empid, managerid, name, title, lvl
) as (
  select empid, managerid, 
         name, title, 1 lvl
  from   t
  where  empid = 1
  union all
  select t.empid, t.managerid, 
         t.name, t.title,
         lvl + 1 lvl
  from   chart c
  join   t
  on     c.empid = t.managerid
) search depth first by empid set seq,
  jdata as (
  select case
           /* The employee has reports */
           when lead ( lvl ) over ( order by seq ) > lvl then
             '{"name": "' || name ||
             '", "title": "' || title ||
             '", "children": ['
           else
             json_object ( 'name' value name, 'title' value title )
         end ||
         case
           /* Close arrays & objects */
           when lead ( lvl ) over ( order by seq ) is null then
             lpad ( ']}', ( lvl - 1 ) * 2, ']}' ) 
           when lead ( lvl ) over ( order by seq ) < lvl then
             lpad ( ']}', ( lvl - lead ( lvl ) over ( order by seq ) ) * 2, ']}' )
         end ||
         case
           /* Add closing commas */
           when lead ( lvl ) over ( order by seq ) <= lvl then
             ','
         end j,
         lead ( lvl ) over ( order by seq ) nlvl,
         seq, lvl
  from   chart
)
  select json_query ( 
           listagg ( j ) 
             within group ( order by seq ), 
           '$' returning varchar2 pretty
         ) chart_json
  from   jdata;

CHART_JSON                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
{
  "name" : "John",
  "title" : "GM",
  "children" :
  [
    {
      "name" : "Smith",
      "title" : "Manager"
    },
    {
      "name" : "Jason",
      "title" : "Manager",
      "children" :
      [
        {
          "name" : "Will",
          "title" : "IP1"
        },
        {
          "name" : "Jade",
          "title" : "AM",
          "children" :
          [
            {
              "name" : "Mark",
              "title" : "IP2"
            },
            {
              "name" : "Jane",
              "title" : "AM2"
            }
          ]
        }
      ]
    },
    {
      "name" : "Tamar",
      "title" : "M1"
    },
    {
      "name" : "Dory",
      "title" : "M2"
    }
  ]
}

在Oracle中将父子行转换为JSON

1 个答案: