L2 Construct: select
etl selectDescription
SelectColumnsEndpoint extracts specified columns from an input Table.
This endpoint accepts a Table and a list of column names to select. It returns a new Table containing only the specified columns, preserving the order of rows from the original Table. If a specified column doesn't exist in the input Table, an error is returned.
Use this endpoint to reduce the number of columns in a Table, focusing on specific data points of interest. This can be particularly useful for data analysis, reporting, or preparing data for further processing.
L2 Data
- Provider: pontus
- Module: etl
- Action: select
Example Step
{
"name": "insert-your-step-name",
"type": "l2",
"l2_data": {
"provider": "pontus",
"module": "etl",
"action": "select",
"metadata": {}
}
}
Input
Example
{
"table": {
"headers": [
"ID",
"Name",
"Age",
"City"
],
"rows": [
[
"1",
"Alice",
"30",
"New York"
],
[
"2",
"Bob",
"25",
"San Francisco"
]
]
},
"columns": [
"ID",
"Name"
]
}Schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://pontus.bpa/pkgs/l2/pontus/etl/select-columns-input",
"$ref": "#/$defs/SelectColumnsInput",
"$defs": {
"SelectColumnsInput": {
"properties": {
"table": {
"$ref": "#/$defs/Table"
},
"columns": {
"items": {
"type": "string"
},
"type": "array"
}
},
"additionalProperties": false,
"type": "object",
"required": ["table", "columns"]
},
"Table": {
"properties": {
"name": {
"type": "string"
},
"description": {
"type": "string"
},
"headers": {
"items": {
"type": "string"
},
"type": "array"
},
"rows": {
"items": {
"items": true,
"type": "array"
},
"type": "array"
}
},
"additionalProperties": false,
"type": "object",
"required": ["headers", "rows"]
}
}
}
Output
Example
{
"result_table": {
"headers": [
"ID",
"Name"
],
"rows": [
[
"1",
"Alice"
],
[
"2",
"Bob"
]
]
}
}Schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://pontus.bpa/pkgs/l2/pontus/etl/select-columns-output",
"$ref": "#/$defs/SelectColumnsOutput",
"$defs": {
"SelectColumnsOutput": {
"properties": {
"result_table": {
"$ref": "#/$defs/Table"
}
},
"additionalProperties": false,
"type": "object",
"required": ["result_table"]
},
"Table": {
"properties": {
"name": {
"type": "string"
},
"description": {
"type": "string"
},
"headers": {
"items": {
"type": "string"
},
"type": "array"
},
"rows": {
"items": {
"items": true,
"type": "array"
},
"type": "array"
}
},
"additionalProperties": false,
"type": "object",
"required": ["headers", "rows"]
}
}
}