数据库查询，并且sql直接返回json格式

SELECT
    JSON_ARRAYAGG(
        JSON_OBJECT(
            'groupId', g.id,
            'groupName', g.NAME,
            'groupColor', g.group_color,
            'num', COALESCE(c.num, 0),
            'type', g.type
        )
    ) AS result
FROM
    xbd_group g
LEFT JOIN (
    SELECT
        group_id,
        COUNT(id) AS num
    FROM
        xbd_customer_1
    WHERE
        y_uid = 1
    GROUP BY
        group_id
) c ON g.id = c.group_id
WHERE
    g.y_uid IN (0, 1)
AND g.STATUS = 0
ORDER BY
    g.id
LIMIT 10
OFFSET 0;

返回值：

[
    {
        "num": 2,
        "type": 1,
        "groupId": 1,
        "groupName": "手机通讯录",
        "groupColor": null
    },
    {
        "num": 31,
        "type": 4,
        "groupId": 4,
        "groupName": "未分组",
        "groupColor": null
    }
]