小编Ava*_*gut的帖子

我一直在python中使用pandas,我通常会将数据帧写入我的db表,如下所示.我现在正在迁移到Django,如何通过名为MyModel的模型将相同的数据帧写入表中？援助真的很感激.

# Original pandas code
    engine = create_engine('postgresql://myuser:mypassword@localhost:5432/mydb', echo=False)
    mydataframe.to_sql('mytable', engine,if_exists='append',index=True)

我有一个ms访问表,跟踪50个产品及其每日销售量.我想使用vba 1 csv文件(包括标题)导出每个产品,显示记录集中的每日卷而不将记录集保存到永久查询.我正在使用下面的代码,但我被困在代码中下面突出显示的实际导出点.任何帮助解决这个问题表示赞赏.

Dim rst As Recordset
Dim rstId As Recordset

    SQLExportIds = "SELECT DISTINCT tblDailyVols.SecId FROM tblDailyVols WHERE tblDailyVols.IsDeleted=False"
    Set rstId = CurrentDb.OpenRecordset(SQLExportIds)
        If rstId.EOF = True Then
            MsgBox "No Products Found"
            Exit Sub
        End If

        Do While rstId.EOF = False
            SecId = rstId.Fields("SecId")
            SQLExportQuotes = " SELECT tblDailyVols.ID , tblDailyVols.TradedVolume, tblDailyVols.EffectiveDate  FROM tblDailyVols "
            SQLExportQuotes = SQLExportQuotes & " WHERE  tblDailyVols.IsDeleted=False and tblDailyVols.ID = " & SecId
            SQLExportQuotes = SQLExportQuotes & " ORDER BY tblDailyVols.EffectiveDate "


        Set rst …

我在PostgreSQL上有一个遗留数据库,有一个简单的产品表,有2列(productid,productname),有70个产品.我正在尝试使用Django作为前端,我有下面的模型和模型表单.保存过程失败,出现以下错误.

duplicate key value violates unique constraint "productidentifier"
DETAIL:  Key (productid)=(4) already exists.

任何人都可以帮助纠正错误.我已在Postgres表上确认索引获取序列设置正确,期望值应为72.请参见下面的模型,表单和视图.

#models.py
class Products(models.Model):
    productid = models.AutoField(primary_key=True)
    productname = models.TextField(verbose_name='Product Name')

    class Meta:
        managed = False
#Views.py
def new_product(request):
    if request.method == 'POST':
        form= forms.EditProductForm(request.POST)
        if form.is_valid():
            product = form.save()
            return redirect('views.full_product_list')   
    else:
        form = forms.EditProductForm()
        return render(request, 'edit_product.html', {'form': form})

#forms.py
class EditProductForm(forms.ModelForm):
    productname = forms.CharField(widget=forms.TextInput(attrs={'class':'form-control'}))

    class Meta:
        model = models.Products
        fields = ('productname')

我正在尝试对相关对象进行以下过滤的不同项目的SQL Alchemy查询，其等效于以下查询：

SELECT distinct items.item_id, items.item_name
FROM items
INNER JOIN categories as cat on items.category_id = cat.category_id
INNER JOIN stores on cat.store_id = stores.store_id
WHERE store.store_id = 123    

我已经创建了以下包含外键的模型，但是当我在下面运行查询时，它不能正确过滤。

items_query = (db.session.query(Store, Item)
               .filter(Store.store_id == 123)
               ).all()



#SQL Alchemy Models 
class Store(db.Model):
    __tablename__ = 'stores'
    store_id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    store_name = db.Column(db.String(100), unique=True, nullable=False)

    def __repr__(self):
        return '<Store>'+str(self.store_name)

class Category(db.Model):
    __tablename__ = 'categories'
    category_id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    category_name = db.Column(db.String(100), unique=True, nullable=False)
    store_id = db.Column(db.Integer, db.ForeignKey('stores.store_id'))
    store = …