Django：如何查詢多個表中的多個字段

Question

我有以下我知道有效的SQL語句：

SELECT year_table.year_value, races.race_name, results.category,results.position 
FROM races, year_table, results
WHERE year_table.year_value = variable AND year_table.year_id = results.year_id;

您如何將其轉換為Django查詢語句？

這些是模型：

class YearTable(models.Model):
    year_id = models.IntegerField(primary_key=True)
    year_value = models.CharField(max_length=10, blank=True)
    class Meta:
        managed = False
        db_table = 'year_table'

class Races(models.Model):
    race_id = models.IntegerField(primary_key=True)
    race_name = models.CharField(max_length=50, blank=True)
    class Meta:
        managed = False
        db_table = 'races'

class Results(models.Model):
    year = models.ForeignKey('YearTable')
    race = models.ForeignKey(Races)
    category = models.CharField(max_length=100)
    position = models.CharField(max_length=10)
    class Meta:
        managed = False
        db_table = 'results'

Answer 1

您可以從結果中獲取所有信息，並使用select_related加入其他模型。

results = Results.objects.all().select_related('year', 'race')