SQL语句

方法一

SELECT
	row_to_json ( fc ) 
FROM
	(
	SELECT
		'FeatureCollection' AS TYPE,
		array_to_json ( ARRAY_AGG ( f ) ) AS features 
	FROM
		(
		SELECT
			'Feature' AS TYPE,
			ST_AsGeoJSON ( '数据库中的空间字段' ) :: json AS geometry,
			( SELECT row_to_json ( T ) FROM ( SELECT '要查询的字段，逗号分割' ) AS T ) AS properties 
		FROM
			'数据库表名' 
		WHERE
			'数据库中的空间字段' IS NOT NULL 
		) AS f 
	) AS fc

方法二

SELECT
	json_build_object (
		'type',
		'FeatureCollection',
		'features',
		jsonb_agg (
			json_build_object ( 'type', 'Feature', 'geometry', ST_AsGeoJSON ( '数据库中的空间字段' ) :: json, 'properties', json_build_object ( '返回字段名称A', '要查询的字段A', '返回字段名称B', '要查询的字段B' ) ) 
		) 
	) 
FROM
	'数据库表名' 
WHERE
	'数据库中的空间字段' IS NOT NULL 

结果

参考地址
❤️postgis函数❤️
❤️row_to_json的使用❤️