Question

我的表格如下：

CREATE TABLE IF NOT EXISTS "points" (
    "id" INTEGER NOT NULL,
    "lat" DOUBLE PRECISION NOT NULL,
    "lon" DOUBLE PRECISION NOT NULL
);

INSERT INTO "points" ("id", "lat", "lon") VALUES
    (1,51.11,-0.11),
    (2,51.12,-0.12),
    (3,51.13,-0.13),
    (4,51.14,-0.14),
    (5,52.44,-2.44),
    (6,52.45,-2.45),
    (7,52.46,-2.46),
    (8,52.47,-2.47);

如何从两列（lat，lon）中选择数据作为表中的JSON数组，并在一列（id）中进行排序？结果应该是：

[
    [51.11,-0.11],[51.12,-0.12],
    [51.13,-0.13],[51.14,-0.14],
    [44,-2.44],[52.45,-2.45],
    [52.46,-2.46],[52.47,-2.47]
]

Answer 1

select to_json(array_agg(array[lat,lon] order by id))
from points
;
                                                      to_json                                                      
-------------------------------------------------------------------------------------------------------------------
 [[51.11,-0.11],[51.12,-0.12],[51.13,-0.13],[51.14,-0.14],[52.44,-2.44],[52.45,-2.45],[52.46,-2.46],[52.47,-2.47]]

从两列中选择数据作为一列中的数组排序并在另一列中进行分组

1 个答案: