> ## Documentation Index
> Fetch the complete documentation index at: https://docs.datris.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Dropping Columns

> Remove columns from data

You can exclude columns from the output by defining a **destination schema** that omits unwanted columns. No special configuration is needed — simply remove the columns from the destination schema that you don't want in the output.

## How It Works

When a destination schema (`destination.schemaProperties`) is defined, only the columns listed in it are written to the destination. Columns present in the source but absent from the destination schema are dropped.

## Example

Given source data with columns `id`, `name`, `email`, `internal_code`, `created_at`:

```json theme={null}
{
  "name": "employees",
  "source": {
    "schemaProperties": {
      "fields": [
        {"name": "id", "type": "int"},
        {"name": "name", "type": "string"},
        {"name": "email", "type": "string"},
        {"name": "internal_code", "type": "string"},
        {"name": "created_at", "type": "timestamp"}
      ]
    },
    "fileAttributes": {
      "csvAttributes": {"delimiter": ",", "header": true, "encoding": "UTF-8"}
    }
  },
  "destination": {
    "schemaProperties": {
      "fields": [
        {"name": "id", "type": "int"},
        {"name": "name", "type": "string"},
        {"name": "email", "type": "string"}
      ]
    },
    "database": {
      "dbName": "mydb",
      "schema": "public",
      "table": "employees",
      "usePostgres": true
    }
  }
}
```

In this example, `internal_code` and `created_at` are present in the source but excluded from the destination schema, so they are dropped from the output.

## Notes

* Column dropping applies to delimited/CSV row data, where each row is projected to the destination columns. JSON and XML pipelines use a single raw `_json`/`_xml` document that passes through without per-column projection, so column dropping does not apply to them.
* The destination schema field names must match source schema field names (case-insensitive)
* Column order in the destination schema determines the output column order