---
title: Chart Parameters Reference
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sidebar_position: 4
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---

## Chart Parameters

Chart parameters are stored as a JSON encoded string in the `slices.params` column and are often referenced throughout the code as form-data. Currently the form-data is neither versioned nor typed as thus is somewhat free-formed. Note in the future there may be merit in using something like [JSON Schema](https://json-schema.org/) to both annotate and validate the JSON object in addition to using a Mypy `TypedDict` (introduced in Python 3.8) for typing the form-data in the backend. This section serves as a potential primer for that work.

The following tables provide a non-exhaustive list of the various fields which can be present in the JSON object grouped by the Explorer pane sections. These values were obtained by extracting the distinct fields from a legacy deployment consisting of tens of thousands of charts and thus some fields may be missing whilst others may be deprecated.

Note not all fields are correctly categorized. The fields vary based on visualization type and may appear in different sections depending on the type. Verified deprecated columns may indicate a missing migration and/or prior migrations which were unsuccessful and thus future work may be required to clean up the form-data.

### Datasource & Chart Type

| Field             | Type     | Notes                                |
| ----------------- | -------- | ------------------------------------ |
| `database_name`   | _string_ | _Deprecated?_                        |
| `datasource`      | _string_ | `<datasource_id>__<datasource_type>` |
| `datasource_id`   | _string_ | _Deprecated?_ See `datasource`       |
| `datasource_name` | _string_ | _Deprecated?_                        |
| `datasource_type` | _string_ | _Deprecated?_ See `datasource`       |
| `viz_type`        | _string_ | The **Visualization Type** widget    |

### Time

| Field              | Type     | Notes                                 |
| ------------------ | -------- | ------------------------------------- |
| `granularity_sqla` | _string_ | The SQLA **Time Column** widget       |
| `time_grain_sqla`  | _string_ | The SQLA **Time Grain** widget        |
| `time_range`       | _string_ | The **Time range** widget             |

### GROUP BY

| Field                     | Type            | Notes             |
| ------------------------- | --------------- | ----------------- |
| `metrics`                 | _array(string)_ | See Query section |
| `order_asc`               | -               | See Query section |
| `row_limit`               | -               | See Query section |
| `timeseries_limit_metric` | -               | See Query section |

### NOT GROUPED BY

| Field           | Type            | Notes                   |
| --------------- | --------------- | ----------------------- |
| `order_by_cols` | _array(string)_ | The **Ordering** widget |
| `row_limit`     | -               | See Query section       |

### Y Axis 1

| Field           | Type | Notes                                              |
| --------------- | ---- | -------------------------------------------------- |
| `metric`        | -    | The **Left Axis Metric** widget. See Query section |
| `y_axis_format` | -    | See Y Axis section                                 |

### Y Axis 2

| Field      | Type | Notes                                               |
| ---------- | ---- | --------------------------------------------------- |
| `metric_2` | -    | The **Right Axis Metric** widget. See Query section |

### Query

| Field                                                                                                  | Type                                              | Notes                                             |
| ------------------------------------------------------------------------------------------------------ | ------------------------------------------------- | ------------------------------------------------- |
| `adhoc_filters`                                                                                        | _array(object)_                                   | The **Filters** widget                            |
| `extra_filters`                                                                                        | _array(object)_                                   | Another pathway to the **Filters** widget.<br/>It is generally used to pass dashboard filter parameters to a chart.<br/>It can be used for appending additional filters to a chart that has been saved with its own filters on an ad-hoc basis if the chart is being used as a standalone widget.<br/><br/>For implementation examples see : [utils test.py](https://github.com/apache/superset/blob/66a4c94a1ed542e69fe6399bab4c01d4540486cf/tests/utils_tests.py#L181)<br/>For insight into how superset processes the contents of this parameter see: [exploreUtils/index.js](https://github.com/apache/superset/blob/93c7f5bb446ec6895d7702835f3157426955d5a9/superset-frontend/src/explore/exploreUtils/index.js#L159)                         |
| `columns`                                                                                              | _array(string)_                                   | The **Breakdowns** widget                         |
| `groupby`                                                                                              | _array(string)_                                   | The **Group by** or **Series** widget             |
| `limit`                                                                                                | _number_                                          | The **Series Limit** widget                       |
| `metric`<br/>`metric_2`<br/>`metrics`<br/>`percent_metrics`<br/>`secondary_metric`<br/>`size`<br/>`x`<br/>`y` | _string_,_object_,_array(string)_,_array(object)_ | The metric(s) depending on the visualization type |
| `order_asc`                                                                                            | _boolean_                                         | The **Sort Descending** widget                    |
| `row_limit`                                                                                            | _number_                                          | The **Row limit** widget                          |
| `timeseries_limit_metric`                                                                              | _object_                                          | The **Sort By** widget                            |

The `metric` (or equivalent) and `timeseries_limit_metric` fields are all composed of either metric names or the JSON representation of the `AdhocMetric` TypeScript type. The `adhoc_filters` is composed of the JSON represent of the `AdhocFilter` TypeScript type (which can comprise of columns or metrics depending on whether it is a WHERE or HAVING clause). The `all_columns`, `all_columns_x`, `columns`, `groupby`, and `order_by_cols` fields all represent column names.

### Chart Options

| Field          | Type      | Notes                       |
| -------------- | --------- | --------------------------- |
| `color_picker` | _object_  | The **Fixed Color** widget  |
| `label_colors` | _object_  | The **Color Scheme** widget |
| `normalized`   | _boolean_ | The **Normalized** widget   |

### Y Axis

| Field            | Type     | Notes                        |
| ---------------- | -------- | ---------------------------- |
| `y_axis_2_label` | _N/A_    | _Deprecated?_                |
| `y_axis_format`  | _string_ | The **Y Axis Format** widget |
| `y_axis_zero`    | _N/A_    | _Deprecated?_                |

Note the `y_axis_format` is defined under various section for some charts.

### Other

| Field          | Type     | Notes |
| -------------- | -------- | ----- |
| `color_scheme` | _string_ |       |

### Unclassified

| Field                         | Type  | Notes |
| ----------------------------- | ----- | ----- |
| `add_to_dash`                 | _N/A_ |       |
| `code`                        | _N/A_ |       |
| `collapsed_fieldsets`         | _N/A_ |       |
| `comparison type`             | _N/A_ |       |
| `country_fieldtype`           | _N/A_ |       |
| `default_filters`             | _N/A_ |       |
| `entity`                      | _N/A_ |       |
| `expanded_slices`             | _N/A_ |       |
| `filter_immune_slice_fields`  | _N/A_ |       |
| `filter_immune_slices`        | _N/A_ |       |
| `flt_col_0`                   | _N/A_ |       |
| `flt_col_1`                   | _N/A_ |       |
| `flt_eq_0`                    | _N/A_ |       |
| `flt_eq_1`                    | _N/A_ |       |
| `flt_op_0`                    | _N/A_ |       |
| `flt_op_1`                    | _N/A_ |       |
| `goto_dash`                   | _N/A_ |       |
| `import_time`                 | _N/A_ |       |
| `label`                       | _N/A_ |       |
| `linear_color_scheme`         | _N/A_ |       |
| `new_dashboard_name`          | _N/A_ |       |
| `new_slice_name`              | _N/A_ |       |
| `num_period_compare`          | _N/A_ |       |
| `period_ratio_type`           | _N/A_ |       |
| `perm`                        | _N/A_ |       |
| `rdo_save`                    | _N/A_ |       |
| `refresh_frequency`           | _N/A_ |       |
| `remote_id`                   | _N/A_ |       |
| `resample_fillmethod`         | _N/A_ |       |
| `resample_how`                | _N/A_ |       |
| `rose_area_proportion`        | _N/A_ |       |
| `save_to_dashboard_id`        | _N/A_ |       |
| `schema`                      | _N/A_ |       |
| `series`                      | _N/A_ |       |
| `show_bubbles`                | _N/A_ |       |
| `slice_name`                  | _N/A_ |       |
| `timed_refresh_immune_slices` | _N/A_ |       |
| `userid`                      | _N/A_ |       |
