我有一个如下表:
id (VARCHAR) | field1 (text) | attributes (jsonb)
--------------+---------------+----------------------------------
123 | a | {"age": "1", "place": "TX"}
456 | b | {"age": "2", "name": "abcdef"}
789 | |
098 | c | {"name": ["abc", "def", "ghi"]}
想将其转换为:
<Company id="123" field="a">
<CompanyTag tagName="age" tagValue="1"/>
<CompanyTag tagName="place" tagValue="TX"/>
</Company>
<Company id="456" field="b">
<CompanyTag tagName="age" tagValue="2"/>
<CompanyTag tagName="name" tagValue="abcdef"/>
</Company>
<Company id="789"/>
<Company id="098" field="c">
<CompanyTag tagName="name" tagValue="abc"/>
<CompanyTag tagName="name" tagValue="def"/>
<CompanyTag tagName="name" tagValue="ghi"/>
</Company>
在@bergi和@Georges Martin的帮助下,Post能够使用以下查询转换非数组:
SELECT XMLELEMENT(
NAME "Company",
XMLATTRIBUTES(id AS id, field1 AS field),
(SELECT XMLAGG(
XMLELEMENT(
NAME "companyTag",
XMLATTRIBUTES(
attr.key AS "tagName",
attr.value AS "tagValue"
)
)
) FROM JSONB_EACH_TEXT(attributes) AS attr)
) FROM comp_emp;
但是,数组值显示如下:
<Company id="098" field="c">
<CompanyTag tagName="name"tagValue="["abc", "def", "ghi"]"/>
我不想在查询中特别提到键("tagName"(,因为这可能会有所不同。假设这是由于JSONB_EACH_TEXT提取了最外层的值而导致的。有其他选择吗?
请引导我朝正确的方向走。
如果处理数组,则需要额外的jsonb_array_elements_text
来提取值。完成横向连接:
SELECT XMLAGG(
XMLELEMENT(
NAME "CompanyTag",
XMLATTRIBUTES(
attr.key AS "tagName",
values.element AS "tagValue"
)
)
) FROM jsonb_each(attributes) AS attr,
LATERAL jsonb_array_elements_text(CASE jsonb_typeof(attr.value)
WHEN 'array' THEN attr.value
ELSE jsonb_build_array(attr.value)
END) AS values(element)
(在线演示,带完整查询(