在postgresql

Question

我有一个表，该表具有三列：id，geometry和一个text列，它是一个由几列组成的聚合数组。我想创建一个geojson对象，但它不允许我这样做。你能帮我吗！

T1
id  |  tag_frequency   | geom 
1   |  {"[frame,1]", "[big,3]"}    | 00000046875

这是我用来创建对象并写入文件的查询

copy (SELECT jsonb_build_object(
 'type',     'FeatureCollection',
'features', jsonb_agg(feature)
)
FROM (
SELECT jsonb_build_object(
  'type',       'Feature',
'id',         id,
'geometry',   ST_AsGeoJSON(geom)::jsonb,
'properties', to_jsonb(inputs) - 'id' - 'geom'
) AS feature
FROM (
SELECT * FROM T1
) inputs
) features)to '...\test.geojson';

但是，已使用以下查询从另一个表中检索了标签列，以使与每个ID相关联的所有单词的出现频率都达到这一水平。

SELECT id, geom, array_agg('[' || tags || ',' || frequency || ']') 
as tag_frequency
FROM 
    (SELECT id, geom, tags, count(tags) AS frequency 
    FROM tt 
    GROUP BY id, geom, tags order by tags) AS RES
GROUP BY id, geom;