好的,也许有人知道更好的解决方案,但是经过一些研究,我无法使用纯ef 核心来实现,所以我使用了FromSql
var queryable = qLogs.FromSql("select * from \"" + tableName + "\" order by \"" + orderField + "\"");
var result = qCars.Select(x => new RouteModel
{
Mileage = Math.Round(
queryable
.Where(y => y.CarId == x.Id)
.Select(y => PostgisExtensions.ST_LengthSpheroid(
PostgisExtensions.ST_MakeLine(
PostgisExtensions.ST_GeomFromText(y.Location.AsText(), PostgisConstants.MetricSrid)
),
PostgisConstants.SpheroidWgs84)
)
.FirstOrDefault() / 1000),
.....
所以现在我可以orderby
在没有groupby
or的情况下使用子选择distinct on
。在没有任何 ef 核心警告的情况下完美运行并生成预期的查询:
SELECT ROUND(COALESCE((
SELECT ST_LengthSpheroid(ST_MakeLine(ST_GeomFromText(ST_AsText(x0."Location"), 4326)), 'SPHEROID["WGS 84",6378137,298.257223563]')
FROM (
select * from "Logs" order by "FixedAt"
) AS x0
WHERE (x0."CarId" = x."Id")
LIMIT 1
), 0.0) / 1000.0) AS "Mileage",
.....