django，使用唯一字段编辑表单，form.is_valid 返回 false

Question

class modelA(..):
    fieldA = ...     unique
    fieldB = ...     unique

    class Meta:
        unique_together = [['fieldA','fieldB']]


class formA(modelform):

    class Meta:
        model = modelA
        field = ['fieldA','fieldB']


def viewA(request):
    if request.method == 'POST':
        form = formA(request.POST)
        if form.is_valid():          here return false !!!!!
            ......

在edit表单中，点击提交按钮更新数据库时，form.is_valid()返回false，因为unique_together校验，如何解决？

Answer 1

您应该将要编辑的模型实例传递给 instance 参数:

from django.shortcuts import get_object_or_404

def viewA(request, pk):
    obj = get_object_or_404(modelA, pk=pk)
    if request.method == 'POST':
        form = formA(request.POST, instance=obj)
        if form.is_valid():
            ...