加载并检查指标视图
本操作指南演示如何将 Databricks Metric View 加载到 Tabular Editor 中,并使用 C# Script 探索其结构。这是进行其他所有 Metric View 操作的基础。
Note
这些操作指南适用于 Tabular Editor 3.26.2 及更高版本。较早版本不支持本文所示的 v1.1 指标视图功能。
为这些代码示例加载示例 Metric View
开始前,请确保你已打开 Tabular Editor 3,并已打开一个表格模型;如果没有,也可以新建一个模型。
本操作指南使用一个示例电商 Metric View 来表示销售数据,其中三个维度表(product、customer、date)连接到一个事实表(orders)。使用下面任一方法来加载它(“下载并加载”或“复制并反序列化”),然后继续阅读本操作指南的其余内容。你可以在与本示例其余部分相同的 C# Script 中运行任一命令;也可以先在单独的 C# Script 中运行该命令,再在另一个 C# Script 中运行本示例的其余部分。
下载 sample-metricview.yaml
然后按路径加载:
SemanticBridge.MetricView.Load("C:/path/to/sample-metricview.yaml");
访问已加载的 Metric View
加载完成后,可在任何脚本中通过 SemanticBridge.MetricView.Model 访问该 Metric View。这会返回一个 Metric View 的 View 对象,它是 Metric View 对象图 的根节点。
var sb = new System.Text.StringBuilder();
var view = SemanticBridge.MetricView.Model;
sb.AppendLine($"Version: {view.Version}");
sb.AppendLine($"Source (fact table): {view.Source}");
Output(sb.ToString());
输出
Version: 1.1
Source (fact table): sales.fact.orders
检查 Metric View 的连接(维度表)
Metric View 的 Joins 属性包含与事实表连接的维度表。
var sb = new System.Text.StringBuilder();
var view = SemanticBridge.MetricView.Model;
sb.AppendLine($"Number of joins: {view.Joins.Count}");
sb.AppendLine("");
foreach (var join in view.Joins)
{
sb.AppendLine($"Join: {join.Name}");
sb.AppendLine($" Source: {join.Source}");
sb.AppendLine($" On: {join.On}");
sb.AppendLine($" Cardinality: {join.Cardinality?.ToString() ?? "ManyToOne (default)"}");
sb.AppendLine("");
}
Output(sb.ToString());
输出:
Number of joins: 3
Join: product
Source: sales.dim.product
On: source.product_id = product.product_id
Cardinality: ManyToOne
Join: customer
Source: sales.dim.customer
On: source.customer_id = customer.customer_id
Cardinality: ManyToOne
Join: date
Source: sales.dim.date
On: source.order_date = date.date_key
Cardinality: ManyToOne
检查指标视图字段
指标视图的 Fields 属性包含所有字段定义。
var sb = new System.Text.StringBuilder();
var view = SemanticBridge.MetricView.Model;
sb.AppendLine($"Number of fields: {view.Fields.Count}");
sb.AppendLine("");
foreach (var field in view.Fields)
{
sb.AppendLine($"{field.Name,-20} <- {field.Expr}");
}
Output(sb.ToString());
输出:
Number of fields: 6
product_name <- product.product_name
product_category <- product.category
customer_segment <- customer.segment
order_date <- date.full_date
order_year <- date.year
order_month <- date.month_name
查看 Metric View 度量值
Metric View 的 Measures 属性包含所有 Metric View 度量值定义及其聚合表达式。
var sb = new System.Text.StringBuilder();
var view = SemanticBridge.MetricView.Model;
sb.AppendLine($"Number of measures: {view.Measures.Count}");
sb.AppendLine("");
foreach (var measure in view.Measures)
{
sb.AppendLine($"{measure.Name,-20} = {measure.Expr}");
}
Output(sb.ToString());
输出:
Number of measures: 6
total_revenue = SUM(revenue)
gross_margin = SUM(revenue) - SUM(cost)
order_count = COUNT(*)
avg_order_value = AVG(revenue)
revenue_to_budget = (SUM(revenue) - SUM(budget)) / SUM(budget)
unique_customers = COUNT(DISTINCT customer_id)
生成完整摘要
下面是一段完整脚本,用于输出整个 Metric View 的格式化摘要。
var sb = new System.Text.StringBuilder();
var view = SemanticBridge.MetricView.Model;
sb.AppendLine("METRIC VIEW SUMMARY");
sb.AppendLine("===================");
sb.AppendLine("");
sb.AppendLine($"Version: {view.Version}");
sb.AppendLine($"Fact Source: {view.Source}");
sb.AppendLine("");
// Joins
sb.AppendLine($"JOINS ({view.Joins.Count})");
sb.AppendLine("---------");
foreach (var join in view.Joins)
{
sb.AppendLine($" {join.Name,-15} -> {join.Source}");
}
sb.AppendLine("");
// Fields
sb.AppendLine($"FIELDS ({view.Fields.Count})");
sb.AppendLine("--------------");
foreach (var field in view.Fields)
{
sb.AppendLine($" {field.Name,-20} <- {field.Expr}");
}
sb.AppendLine("");
// Measures
sb.AppendLine($"MEASURES ({view.Measures.Count})");
sb.AppendLine("------------");
foreach (var measure in view.Measures)
{
sb.AppendLine($" {measure.Name,-20} = {measure.Expr}");
}
Output(sb.ToString());
输出
METRIC VIEW SUMMARY
===================
Version: 1.1
Fact Source: sales.fact.orders
JOINS (3)
---------
product -> sales.dim.product
customer -> sales.dim.customer
date -> sales.dim.date
FIELDS (6)
--------------
product_name <- product.product_name
product_category <- product.category
customer_segment <- customer.segment
order_date <- date.full_date
order_year <- date.year
order_month <- date.month_name
MEASURES (6)
------------
total_revenue = SUM(revenue)
gross_margin = SUM(revenue) - SUM(cost)
order_count = COUNT(*)
avg_order_value = AVG(revenue)
revenue_to_budget = (SUM(revenue) - SUM(budget)) / SUM(budget)
unique_customers = COUNT(DISTINCT customer_id)
后续步骤
现在你已经能够加载并检查 Metric View 了,你还可以: