TMDL code Skill

Tabular Model Definition Language (TMDL) is a declarative language that represents a Power BI semantic model in text. This skill provides important context when interacting directly with TMDL code.

TMDL Semantics / General Rules

• A TMDL object is declared by specifying the TOM object type followed by its name
• TMDL definition uses a folder structure, where some objects such as tables, culture, perspectives, roles are defined in separate files.
• Objects like partition or measure have default properties that can be assigned after the equals (=) sign that specify the PowerQuery expression or DAX expression respectively.

DO:

• Always learn from existing examples and patterns in the code. For example, existing naming conventions.
• Object names must be enclosed in single quotes if they contain spaces or special characters such as .,=,:,'

DON'T:

• Don't add lineageTag property when creating new objects
• Don't add comments to the TMDL code. TMDL language don't support // comments. It does support descriptions (see Task: Setting descriptions in TMDL objects). But comments can be within Power Query (M) expressions or DAX expressions code blocks.

Example of a TMDL of a semantic model: