Python Plotly Dash：如何为不同的用户展示不同的数据？

Question

我使用 PostgreSQL 查询作为 Plotly Dash 仪表板的数据源。在查询开始时，我通过 v_user 参数定义 UserID 并仅为该用户获取数据，并根据这些数据构建一个仪表板。

import psycopg2
import pandas as pd
import plotly.express as px
import dash
import dash_core_components as dcc
import dash_html_components as html

v_user=111

conn = psycopg2.connect(host="xxxx", port = 5432, database="xxxxx", user="xxxxx", password="xxxxx")
statment= f""" select  month, count(id) as sales from public.orders where user_profile_id={v_user} group by 1"""
df_orders= pd.read_sql_query(statment ,con=conn)
df_orders

app = dash.Dash()

fig = px.bar(df_orders, x="month", y="sales")

app.layout = html.Div([
     html.H1('Sales by Users'),
     html.Div([dcc.Graph(figure=fig)])
])

if __name__ == '__main__':
    app.run_server(debug=True, use_reloader=False)

目标是只显示每个用户的数据，这意味着我需要在 SQL 查询之前更改 v_user 参数。这意味着用户“111”只能看到它的数据，用户“222”只能看到它的数据。怎么做？或者也许还有另一种方法可以为每个用户过滤和显示不同的数据??

Answer 1

在破折号中你有什么是调用回调函数，它获取输入和输出参数在您的情况下，您需要添加一种方法 select 用户 ID 并将其传递给回调函数

import psycopg2
import pandas as pd
import plotly.express as px
import dash
import dash_core_components as dcc
import dash_html_components as html

v_user=111

conn = psycopg2.connect(host="xxxx", port = 5432, database="xxxxx", user="xxxxx", password="xxxxx")
statment= f""" select  month, count(id) as sales from public.orders where user_profile_id={v_user} group by 1"""
df_orders= pd.read_sql_query(statment ,con=conn)
df_orders

app = dash.Dash()

fig = px.bar(df_orders, x="month", y="sales")

app.layout = html.Div([
     html.H1('Sales by Users'),
     html.Div([dcc.Graph(id='graph_1', figure=fig)])
])

if __name__ == '__main__':
    app.run_server(debug=True, use_reloader=False)

@app.callback(
    Output(component_id="graph_1", component_property="figure"),
    [Input(component_id="{add the component that hold the user id}", component_property='value')]
)
def update_dates(user_id):
    conn = psycopg2.connect(host="xxxx", port = 5432, database="xxxxx", 
    user="xxxxx", password="xxxxx")
    statment= f""" select  month, count(id) as sales from public.orders where 
    user_profile_id={user_id} group by 1"""
    df_orders= pd.read_sql_query(statment ,con=conn)
    return px.bar(df_orders, x="month", y="sales")

您需要了解您的用户 ID 在哪里以及何时更改

Python Plotly Dash：如何为不同的用户展示不同的数据？

Python Plotly Dash: How to display different data for the different users?

python

postgresql

plotly-dash

plotly-python