Question

我该如何翻译：

SELECT ExchangeTypes.*, Fixtures.*
FROM Fixtures 
INNER JOIN ExchangeTypes ON Fixtures.ExchangeTypeId = ExchangeTypes.Id 
WHERE ExchangeTypes.LayOdds <= Fixtures.BackOdds

进入Linq - 这是我的基本查询：

        {
        var fixtureDtos = _context.Fixtures   //.Where(c => c.BackOdds >= c.ExchangeType.LayOdds) 
            .Include(c => c.ExchangeType)
            .ToList()
            .Select(Mapper.Map<Fixture, FixtureDto>);

        return Ok(fixtureDtos);
        }

请注意，Fixture和Exchange类型之间已经设置了导航属性（多对1）。

Answer 1

var fixtureDtos = (from m in _context.Fixtures
                  join n in _context.ExchangeTypes
                  on m.ExchangeTypeId = n.Id
                  where n.BackOdds > m.BackOdds
                  select new {/*add columns needed from m and n here*/}).ToList();

Answer 2

我设法在EF导航属性中执行此操作。我在评论的代码中处于正确的位置，但忘记确保所比较的两个字段属于同一类型（在为测试目的而改变一个字段之后）。

这是导航属性linq代码：

        {
        var fixtureDtos = _context.Fixtures.Where(c => c.BackOdds >= c.ExchangeType.LayOdds)  
            .Include(c => c.ExchangeType)
            .ToList()
            .Select(Mapper.Map<Fixture, FixtureDto>);

        return Ok(fixtureDtos);
    }

Linq查询WHERE一个字段是＆gt; =父表中的另一个字段？

2 个答案: