在雪花中查询变体数据

Question

这里是我在示例中使用的数据变量源表。我想查询一个数据，将其从变体src解析为雪花表。

{
    "col1": bool,
    "col2": null,
    "col3": "datetime",
    "col4": int,
    "col5": "string",
    "col6": "string",
    "array": [
        {
            "x": bool,
            "y": null,
            "v": "datetime",
            "z": int,
           "w": "string",
            "q": "string",
            "obj": {
                    "a": "bool",
                     "b": "float"
                   },
    "col7": "datetime"
}
]
}

-我尝试过的这里

SELECT 

     src:col1::string as col1,
     src:col2::string as col2,
     src:col3::string as col3,
     src:col4::string as col4,
     src:col5::string as col5,
     src:col6::string as col6,

     s.value:x::string as S_x,
     s.value:y::string as s_y,
     s.value:v::string as s_v,
     s.value:z::string as s_z,
     s.value:w::string as s_w,
     s.value:q::string as s_q,

     s.value:obj.value:a::string as s_obj_a,
     s.value:obj.value:b::string as s_obj_b,

     src:col7::string as col7 
FROM tblvariant
    , table(flatten(src:s)) s
    ;

一切正常，除了这两列（a，b）为空，而它们应包含其数据。有什么建议吗？非常感谢！

Answer 1

您的示例JSON与您的SQL不匹配。 “阶段”和“元数据”在哪里？无论如何，问题似乎与额外的“值”关键字有关。

create or replace table tblvariant ( src variant )
as select parse_json (' 
{
    "col1": "bool",
    "col2": null,
    "col3": "datetime",
    "col4": "int",
    "col5": "string",
    "col6": "string",
    "stages": [
        {
            "x": "bool",
            "y": null,
            "v": "datetime",
            "z": "int",
           "w": "string",
            "q": "string",
            "obj": {
                    "a": "bool",
                     "b": "float"
                   },
    "col7": "datetime"
}
]
}' );

如您所见，我修改了示例JSON，并将“数组”重命名为“阶段”（根据您的SQL）。此SQL检索a和b的值：

SELECT 
     src:col1::string as col1,
     src:col2::string as col2,
     src:col3::string as col3,
     src:col4::string as col4,
     src:col5::string as col5,
     src:col6::string as col6,
     s.value:x::string as S_x,
     s.value:y::string as s_y,
     s.value:v::string as s_v,
     s.value:z::string as s_z,
     s.value:w::string as s_w,
     s.value:q::string as s_q,

     s.value:obj.a::string as s_obj_a,
     s.value:obj.b::string as s_obj_b,

     src:col7::string as col7 
FROM tblvariant
   , table(flatten(src:stages)) s
   -- , table(flatten(s.value:metadata)) m
    ;

Answer 2

s.value：obj 。value：a ::作为s_obj_a的字符串，

s.value：obj 。value：b ::作为s_obj_b的字符串，

可以使用dot (.) notation来访问对象的键。您无需使用.即可访问这些字段：

GET_PATH (:) operator

[您也不需要在GET_PATH数组中的:对象上运行第二个

s.value:metadata.a::string as s_m_a,
s.value:metadata.b::string as s_m_b,

，除非您确实确实每个FLATTEN键需要一个排他，假设FLATTEN是对象类型，而不是嵌套数组。如果您只想将值提取到与每个数组行相同的级别，则只需使用上面的命令就足够了。