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Field query refers to how to specify the contents of the SQL WHERE clause. They are used as keyword arguments to QuerySet's filter(), exclude() and get() methods.
The default lookup type is exact.
The following table lists all field query parameters:
| field name | illustrate |
|---|---|
| exact | exact match |
| iexact | Case-insensitive exact match |
| contains | contains matches |
| icontains | Case-insensitive containment match |
| in | matches within |
| gt | more than the |
| gte | greater or equal to |
| lt | less than |
| lte | less than or equal to |
| startswith | match from the beginning |
| istartswith | Case-insensitive match from the beginning |
| endswith | match from the end |
| iendswith | Case-insensitive match from the end |
| range | range match |
| date | date match |
| year | years |
| month | month |
| day | date |
| week | which week |
| week_day | which day |
| time | time |
| hour | Hour |
| minute | minute |
| second | Second |
| isnull | Determine if it is empty |
| search | Deprecated in 1.10 |
| regex | case-sensitive regular matching |
| iregex | Case-insensitive regular matching |
1. exact
Exact match. Default lookup type!
Entry.objects.get(id__exact=14)
Entry.objects.get(id__exact=None)2. iexact
Case-insensitive exact match.
Blog.objects.get(name__iexact='beatles blog')
Blog.objects.get(name__iexact=None)The first query will match 'Beatles Blog', 'beatles blog', 'BeAtLes BLoG' and so on.
3. contains
Case-sensitive containment matching.
Entry.objects.get(headline__contains='Lennon')This will match the title 'Lennon honored today', but not 'lennon honored today'.
4. icontains
Case-insensitive containment matching.
Entry.objects.get(headline__icontains='Lennon')5. in
Find in the given list.
Entry.objects.filter(id__in=[1, 3, 4])Instead of providing a list of literal values, you can also use a dynamic queryset:
inner_qs = Blog.objects.filter(name__contains='Cheddar')
entries = Entry.objects.filter(blog__in=inner_qs)Or values_list()the QuerySet obtained from values() or as the object of the comparison:
inner_qs = Blog.objects.filter(name__contains='Ch').values('name')
entries = Entry.objects.filter(blog__name__in=inner_qs)The following example will generate an exception because an attempt is made to extract the value of two fields, but the query only needs the value of one field:
# 错误的实例，将弹出异常。
inner_qs = Blog.objects.filter(name__contains='Ch').values('name', 'id')
entries = Entry.objects.filter(blog__name__in=inner_qs)6. gt
more than the
Entry.objects.filter(id__gt=4)7. gte
greater than or equal to
8. lt
less than
9. lte
less than or equal to
10. startswith
Case sensitive, match from start position.
Entry.objects.filter(headline__startswith='Lennon')11. istartswith
Case-insensitive, matches from the beginning.
Entry.objects.filter(headline__istartswith='Lennon')12. endswith
Case-sensitive, matches starting with the end unknown.
Entry.objects.filter(headline__endswith='Lennon')13. iendswith
Case-insensitive, matches starting with the end unknown.
Entry.objects.filter(headline__iendswith='Lennon')14. range
Range testing (included).
import datetime
start_date = datetime.date(2005, 1, 1)
end_date = datetime.date(2005, 3, 31)
Entry.objects.filter(pub_date__range=(start_date, end_date))Warning: Filtering a DateTimeField with dates will not include the last day, as the boundary is interpreted as "0am on a given date".
15. date
Do a date comparison.
Entry.objects.filter(pub_date__date=datetime.date(2005, 1, 1))
Entry.objects.filter(pub_date__date__gt=datetime.date(2005, 1, 1))When USE_TZTrue, the field will be converted to the current timezone and then filtered.
16. year
Match the year.
Entry.objects.filter(pub_date__year=2005)
Entry.objects.filter(pub_date__year__gte=2005)When USE_TZTrue, datetime fields will be converted to the current time zone before filtering.
17. month
Match months. Round from 1 (January) to 12 (December).
Entry.objects.filter(pub_date__month=12)
Entry.objects.filter(pub_date__month__gte=6)When USE_TZ is True, datetime fields are converted to the current time zone before filtering.
18. day
Matches to a specific day.
Entry.objects.filter(pub_date__day=3)
Entry.objects.filter(pub_date__day__gte=3)When USE_TZ is True, datetime fields are converted to the current time zone before filtering.
19. week
New in Django 1.11. Returns the week number (1-52 or 53) according to ISO-8601, the week starting on Monday, Thursday or the first week before.
Entry.objects.filter(pub_date__week=52)
Entry.objects.filter(pub_date__week__gte=32, pub_date__week__lte=38)When USE_TZ is True, the field is converted to the current timezone and then filtered.
20. week_day
Do a "day of the week" match. Takes an integer value, 1 for Sunday, 2 for Monday, and 7 for Saturday.
Entry.objects.filter(pub_date__week_day=2)
Entry.objects.filter(pub_date__week_day__gte=2)When USE_TZ is True, datetime fields are converted to the current time zone before filtering.
21. time
New in Django 1.11.
Convert the field value to datetime.time format and compare.
Entry.objects.filter(pub_date__time=datetime.time(14, 30))
Entry.objects.filter(pub_date__time__between=(datetime.time(8), datetime.time(17)))When USE_TZ is True, the field is converted to the current time zone and then filtered.
22. hour
Match hours. Take an integer between 0 and 23.
Event.objects.filter(timestamp__hour=23)
Event.objects.filter(time__hour=5)
Event.objects.filter(timestamp__hour__gte=12)When USE_TZ is True, the value will be converted to the current time zone before filtering.
23. minute
Match on minutes. Take an integer between 0 and 59.
Event.objects.filter(timestamp__minute=29)
Event.objects.filter(time__minute=46)
Event.objects.filter(timestamp__minute__gte=29)When USE_TZ is True, the value will be converted to the current time zone before being filtered.
24. second
Match on seconds. Take an integer between 0 and 59.
Event.objects.filter(timestamp__second=31)
Event.objects.filter(time__second=2)
Event.objects.filter(timestamp__second__gte=31)When USE_TZ is True, the value will be converted to the current time zone before filtering.
25. isnull
The value is False or True, equivalent to the SQL statements IS NULL and IS NOT NULL.
Entry.objects.filter(pub_date__isnull=True)26. search
Deprecated since version 1.10.
27. regex
Case-sensitive regular expression matching.
Entry.objects.get(title__regex=r'^(An?|The) +')It is recommended to use raw strings (for example, r'foo' instead of 'foo' ) to pass regular expression syntax.
28. iregex
Case-insensitive regular expression matching.
Entry.objects.get(title__iregex=r'^(an?|the) +')Aggregate function
Django's django.db.modelsmodules provide the following aggregate functions.
1. expression
A string referencing a model field, or a query expression.
2. output_field
The model field used to represent the return value, an optional parameter.
3.**extra
Keyword arguments can provide additional information to the SQL generated by aggregate functions.
4. Avg
class Avg(expression, output_field=FloatField(), **extra)[source]
Returns the average of the given expression, which must be numeric unless specified differently output_field.
默认的别名：<field>__avg
返回类型：float（或指定任何output_field的类型）5. Count
class Count(expression, distinct=False, **extra)[source]
Returns the number of objects associated with expression.
默认的别名：<field>__count
返回类型：int
有一个可选的参数：distinct。如果distinct=True，Count 将只计算唯一的实例。默认值为False。6. Max
class Max(expression, output_field=None, **extra)[source]
Returns the maximum value of expression.
默认的别名：<field>__max
返回类型：与输入字段的类型相同，如果提供则为`output_field`类型7. Min
class Min(expression, output_field=None, **extra)[source]
Returns the minimum value of expression.
默认的别名：<field>__min
返回类型：与输入字段的类型相同，如果提供则为`output_field`类型8. StdDev
class StdDev(expression, sample=False, **extra)[source]
Returns the standard deviation of expression.
默认的别名：<field>__stddev
返回类型：float
有一个可选的参数：sample。默认情况下，返回群体的标准差。如果sample=True，返回样本的标准差。
SQLite 没有直接提供StdDev。9. Sum
class Sum(expression, output_field=None, **extra)[source]
Calculates the sum of all values of expression.
默认的别名：<field>__sum
返回类型：与输入字段的类型相同，如果提供则为output_field类型10. Variance
class Variance(expression, sample=False, **extra)[source]
Returns the variance of expression.
默认的别名：<field>__variance
返回类型：float
有一个可选的参数：sample。
SQLite 没有直接提供Variance。