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This guide covers how to migrate Evidence OSS reports to Evidence Studio. Evidence Studio is a complete reimagining of the Evidence platform - moving from a local development tool to a fully cloud-based development, publishing, and governance platform. Studio provides a web-based IDE with AI assistance, enterprise features like row-level security and SSO, and self-service analytics for end users. Components have powerful new capabilities including built-in aggregations, date grains, and comparisons that eliminate the need for complex SQL.

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Key Differences

FeatureEvidence OSSEvidence Studio
Data UpdatesRequires build processQueries run on page load
Build ProcessRequired for every changeNo build - instant previews
Scale & PerformancePerformant up to ~2M rowsPerformant with hundreds of millions of rows
Query EngineDuckDB WASMClickHouse (managed lakehouse)
DevelopmentLocal IDE (VS Code, etc.)Cloud IDE with AI assistant
Component Syntax<LineChart data={orders} />{% line_chart data="orders" /%}
Component DataRequire inline queriesRun their own queries and aggregations
DeploymentConfigure hosting + build pipelineClick “Publish” button
Access ControlManual implementationRow-level security, page permissions, user groups
AuthenticationManual implementationSSO (Okta, Google, Azure, etc.)
Self-Service OptionsReportsReports + Explore + SQL Console + AI Chat
Data SourcesSQL databases, flat filesSQL databases, flat files + direct cloud storage (S3, GCS, Parquet, Delta Lake, Iceberg)
Reusable SQLVia inline queriesModels feature

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How to Migrate

The easiest way to migrate is to paste your OSS code into the Studio editor and ask the AI assistant to convert it for you. The Evidence team is available to help with your migration. If you have a large project to migrate, book a call with our team for assistance.

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Data Sources

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Connections

Configure connections in the Studio UI. See Data Sources for details.

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Data Sync

Studio syncs full tables from SQL databases on a schedule. This allows Evidence to use an optimized ClickHouse instance to deliver high-performance interactive reports with subsecond interaction times. Studio does not support source SQL queries. If you need to aggregate or join data before loading it into Evidence, you have two options:
  1. Create a view in your database and sync that view to Studio
  2. Use Evidence’s Models feature to join across sources and prepare data for analysis
For bucket connectors (S3, GCS, Azure, R2), Studio connects directly and queries files (Parquet, Delta Lake, Iceberg) without importing.

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SQL Queries

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DuckDB → ClickHouse

Studio uses ClickHouse instead of DuckDB. The syntax is very similar between the two. ClickHouse is optimized for fast performance on huge datasets and supports row-level security, direct connections to storage buckets, and other enterprise features.

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Inline Queries

Write inline queries the same way: 
```sql my_query
select * from orders where date > '2024-01-01'
```
Inline queries do not produce a query viewer on the rendered page. To display results, use a component: 
{% table data="my_query" /%}

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Components

Studio components use a new tag syntax and support aggregations, date grains, comparisons, and other operations without writing SQL.

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Tag Syntax

Evidence OSS: 
<LineChart 
  data={daily_orders} 
  x="date" 
  y="sales" 
/>
Evidence Studio: 
{% line_chart
    data="daily_orders"
    x="date"
    y="sales"
%}
Conversion rules:
  • Replace <> with {% %}
  • Convert component names to snake_case: LineChart → line_chart, DataTable → table, BigValue → big_value
  • Quote all attribute values: x="date" instead of x=date
  • Self-closing tags end with /%} instead of />
  • Closing tags use {% /component_name %} instead of </ComponentName>
Component name mappings:
Evidence OSSEvidence Studio
DataTabletable
BigValuebig_value
LineChartline_chart
BarChartbar_chart
AreaChartarea_chart
ScatterChartscatter_chart
All chart componentsUse snake_case
Multi-line components: Evidence OSS: 
<Tabs>
  <Tab label="Sales">Content</Tab>
</Tabs>
Evidence Studio: 
{% tabs %}
  {% tab label="Sales" %}Content{% /tab %}
{% /tabs %}

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Components Run Their Own Queries

Components can query data and apply aggregations directly. Evidence OSS: 
```sql monthly_sales
select 
  date_trunc('month', order_date) as month,
  sum(sales) as total_sales
from orders
group by month
order by month
```

<LineChart data={monthly_sales} x=month y=total_sales />
Evidence Studio: 
{% line_chart
    data="orders"
    x="order_date"
    y="sum(sales)"
    date_grain="month"
%}
Components support aggregations like sum(), avg(), count(), min(), max(), and more: 
{% big_value data="orders" value="sum(sales)" /%}

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Built-in Date Grains

Components support automatic date grouping with date_grain: day, week, month, quarter, year, hour, day of week, day of month, day of year, week of year, month of year, quarter of year. Evidence OSS: 
```sql monthly_sales
select 
  date_trunc('month', order_date) as month,
  sum(sales) as total_sales
from orders
group by 1
order by 1
```

<LineChart data={monthly_sales} x=month y=total_sales />
Evidence Studio: 
{% line_chart
    data="orders"
    x="order_date"
    y="sum(sales)"
    date_grain="month"
%}

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Built-in Comparisons

Evidence OSS: 
```sql orders_with_comparisons
select
  sum(sales) as num_orders,
  (sum(sales) - lag(sum(sales)) over (order by month)) / lag(sum(sales)) over (order by month) as order_growth
from orders
group by date_trunc('month', order_date) as month
```

<BigValue
  data={orders_with_comparisons}
  value=num_orders
  comparison=order_growth
  comparisonFmt=pct1
  comparisonTitle="MoM"
/>
Evidence Studio: 
{% big_value
    data="orders"
    value="sum(sales)"
    date_range={
        date="order_date"
        range="last 30 days"
    }
    comparison={
        compare_vs="prior period"
    }
/%}

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Unsupported Components

  • DimensionGrid - Not yet supported
  • BoxPlot - Not yet supported

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Inputs and Variables

Studio provides simplified syntax for referencing input variables. Evidence OSS: 
<Dropdown name=category>
  <DropdownOption value="Electronics" />
  <DropdownOption value="Clothing" />
</Dropdown>

```sql filtered_orders
select * from orders 
where category = '${inputs.category.value}'
```

<BarChart data={filtered_orders} x=product y=sales />
Evidence Studio - Using inline SQL: 
{% dropdown
    id="category"
    data="orders"
    value_column="category"
/%}

```sql filtered_orders
select * from orders
where category = {{category}}
```

{% bar_chart
    data="filtered_orders"
    x="product"
    y="sum(sales)"
/%}
Evidence Studio - Using filters attribute: 
{% dropdown
    id="category"
    data="orders"
    value_column="category"
/%}

{% bar_chart
    data="orders"
    x="product"
    y="sum(sales)"
    filters=["category"]
/%}
Evidence Studio - Using where attribute: 
{% dropdown
    id="category"
    data="orders"
    value_column="category"
/%}

{% bar_chart
    data="orders"
    x="product"
    y="sum(sales)"
    where="category = {{category}}"
/%}
See Variables for details.

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Templated Pages

Templated pages are not supported in the same way as in OSS, but a comparable feature will be added to Evidence Studio in the near future. We recommend creating an interactive page using an input variable (e.g., a dropdown) that is connected to all queries and components on the page. This allows users to dynamically filter the entire page based on their selection.

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Getting Help