django查询的时候的一些tips

exact

Performs an exact match:

>>> Entry.objects.get(headline__exact="Man bites dog")

This matches any object with the exact headline Man bites dog.

If you dont provide a lookup type that is, if your keyword argument doesnt contain a double underscore the

lookup type is assumed to be exact .

For example, the following two statements are equivalent:

>>> Blog.objects.get(id__exact=14) # Explicit form

>>> Blog.objects.get(id=14) # __exact is implied

This is for convenience, because exact lookups are the common case.

iexact

字符串比较（大小写无关）

>>> Blog.objects.get(name__iexact='beatles blog')

This will match 'Beatles Blog' , 'beatles blog' , 'BeAtLes BLoG' , and so forth.

 

contains

Performs a case-sensitive containment test:

Entry.objects.get(headline__contains='Lennon')

This will match the headline 'Today Lennon honored' but not 'today lennon honored' .

SQLite doesnt support case-sensitive LIKE statements; when using SQLite,``contains`` acts like icontains .

Escaping Percent Signs and Underscores in LIKE Statements

The field lookups that equate to LIKE SQL statements (iexact , contains , icontains , startswith ,

istartswith , endswith , and iendswith ) will automatically escape the two special characters used in LIKE

statements the percent sign and the underscore. (In a LIKE statement, the percent sign signifies a multiplecharacter

wildcard and the underscore signifies a single-character wildcard.)

This means things should work intuitively, so the abstraction doesnt leak. For example, to retrieve all the

entries that contain a percent sign, just use the percent sign as any other character:

Entry.objects.filter(headline__contains='%')

Django takes care of the quoting for you. The resulting SQL will look something like this:

SELECT ... WHERE headline LIKE '%\%%';

The same goes for underscores. Both percentage signs and underscores are handled for you transparently.

icontains

Performs a case-insensitive containment test:

>>> Entry.objects.get(headline__icontains='Lennon')

Unlike contains , icontains will match 'today lennon honored' .

gt gte lt lte

gt大于

gte大于等于

lt小于

lte小于等于