Entity names

This page explains how to use entity names in your APL query.

APL entities (datasets, tables, columns, and operators) are named. For example, two fields or columns in the same dataset can have the same name if the casing is different, and a table and a dataset may have the same name because they aren’t in the same scope.

Columns

• Column names are case-sensitive for resolving purposes and they have a specific position in the dataset’s collection of columns.
• Column names are unique within a dataset and table.
• In queries, columns are generally referenced by name only. They can only appear in expressions, and the query operator under which the expression appears determines the table or tabular data stream.

Identifier naming rules

Axiom uses identifiers to name various entities. Valid identifier names follow these rules:

• Between 1 and 1024 characters long.
• Allowed characters:
  • Alphanumeric characters (letters and digits)
  • Underscore (_)
  • Space ( )
  • Dot (.)
  • Dash (-)

Identifier names are case-sensitive.

Quote identifiers

Quote an identifier in your APL query if any of the following is true:

• The identifier name contains at least one of the following special characters:
  • Space ( )
  • Dot (.)
  • Dash (-)
• The identifier name is identical to one of the reserved keywords of the APL query language. For example, project or where.

If any of the above is true, you must quote the identifier by putting it in quotations marks (') and square brackets ([]). For example, ['my-field'].

If none of the above is true, you don’t need to quote the identifier in your APL query. For example, myfield. In this case, quoting the identifier name is optional.