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Array Expressions

Work with array/multi-value fields.

Overview​

Array expressions indicate that a field contains array values. Use for database columns that are arrays or JSON arrays.

Basic Syntax​

expression:
  array: true
  sql: array_column

When to Use​

Use array expressions for:

  • Database array columns (PostgreSQL arrays)
  • JSON array fields
  • Multi-value dimensions

Example​

- type: dimension
  name: Tags
  data_type: string
  expression:
    array: true
    sql: tag_array

PostgreSQL Arrays​

For PostgreSQL array columns:

- type: dimension
  name: Product Tags
  data_type: string
  expression:
    array: true
    sql: tags  # PostgreSQL array column

JSON Arrays​

For JSON array fields:

- type: dimension
  name: Categories
  data_type: string
  expression:
    array: true
    sql: json_extract_path_text(categories, 'items')  # JSON array

Best Practices​

  1. Use for multi-value fields - When a field can have multiple values
  2. Test array handling - Verify arrays work in your queries
  3. Document array structure - Add descriptions explaining array format

Next Steps​