Extract Values from a Map

AtScale has a special tool for adding calculated columns that extract key:value pairs from a map.

About this task

A MAP type column contains a delimited list of key:value pairs. Map columns are imported into AtScale as STRING type columns. AtScale does not support the MAP data type, but it does have a special calculated column creation tool for working with strings containing a map. This tool generates a calculated column formula using the REGEXP_EXTRACT function.

Procedure

1. Locate the dataset on the canvas, and open the dataset preview so you can see the sample values.
2. Locate the STRING type column that contains map values (a delimited list of key:value pairs).
3. Locate the column in the dataset, and click the edit icon to open the 'calculated column from map' tool.

note

Note: The 'calculated column from map' tool opens for any STRING type column, regardless if the values are a map or not.

1. In the Delimited list, choose the data type for the key, the delimiter character separating a key and a value, the data type for the value, and the delimiter character separating the key:value pairs.
2. In the Columns list, enter the name of the key whose value you want to extract, and choose the data type of the new calculated column you are adding.
3. (optional) Click Add Column to extract other values from the map. If you click this in error, delete the item from the Columns list.
4. Click Save. Confirm that the new calculated columns were added to the dataset.